Online Etymology Dictionary

paternalism (n.): "feeling of a father for his children," 1851; "government as by a father over his children," 1866, from paternal + -ism. Related: Paternalistic (1890).
paternity (n.): mid-15c., "condition of being a father," from Old French paternité (12c.), from Late Latin paternitatem (nominative paternitas) "fatherly care, fatherhood," from Latin paternus "of a father," from pater (see father (n.)). Originally in the ecclesiastical sense; literal sense first recorded 1580s. Meaning "paternal origin" is from 1868.
paternoster (n.): "the Lord's Prayer," Old English Pater Noster, from Latin pater noster "our father," first words of the Lord's Prayer in Latin. Meaning "set of rosary beads" first recorded mid-13c. Paternoster Row, near St. Paul's in London (similarly named streets are found in other cathedral cities), reflects the once-important industry of rosary bead-making.
path (n.): Old English paþ, pæþ "path, track," from West Germanic *patha- (source also of Old Frisian path, Middle Dutch pat, Dutch pad, Old High German pfad, German Pfad "path"), of uncertain origin. The original initial -p- in a Germanic word is an etymological puzzle. Don Ringe ("From Proto-Indo-European to Proto-Germanic," Oxford 2006) describes it as "An obvious loan from Iranian ..., clearly borrowed after Grimm's Law had run its course." Watkins says the word is "probably borrowed (? via Scythian) from Iranian *path-," from PIE root *pent- "to tread, go, pass" (source of Avestan patha "way;" see find (v.)), but this is too much of a stretch for OED and others. In Scotland and Northern England, commonly a steep ascent of a hill or in a road.
Pathet Lao: communist guerrilla movement and political party in Laos, 1954, from Laotian Thai, literally "Land of the Lao" (see Laos).
pathetic (adj.): 1590s, "affecting the emotions, exciting the passions," from Middle French pathétique "moving, stirring, affecting" (16c.), from Late Latin patheticus, from Greek pathetikos "subject to feeling, sensitive, capable of emotion," from pathetos "liable to suffer," verbal adjective of pathein "to suffer" (see pathos). Meaning "arousing pity, pitiful" is first recorded 1737. Colloquial sense of "so miserable as to be ridiculous" is attested from 1937. Related: Pathetical (1570s); pathetically. Pathetic fallacy (1856, first used by Ruskin) is the attribution of human qualities to inanimate objects.
pathfinder (n.): 1839 (Cooper), from path + finder.
pathless (adj.): 1590s, from path + -less.
patho-: before vowels path-, word-forming element meaning "Suffering, disease," from Greek patho-, comb. form of pathos "suffering, disease" (see pathos).
pathogen (n.): 1880, a back-formation from pathogenic.
pathogenesis (n.): 1876, from patho- + genesis.
pathogenic (adj.): "producing disease," 1836, from French pathogénique, from Greek pathos "disease" (see pathos) + French -génique "producing" (see -gen). Related: Pathogenetic (1838); pathogenicity.
pathognomonic (adj.): 1640s (implied in pathognomonical), from patho- "disease, suffering" + Greek gnomonikos "able to judge," from gnomon "one who knows" (see gnomon).
pathologic (adj.): "pertaining to pathology," 1650s, from Greek pathologikos (see pathology).
pathological (adj.): 1680s, "pertaining to disease," formed in English from pathologic + -al (1). Sense of "worthy to be a subject of pathology, morbid, excessive" (as in pathological liar) is attested from 1845. Related: Pathologically.
pathologist (n.): 1640s, from pathology + -ist.
pathology (n.): "science of diseases," 1610s, from French pathologie (16c.), from medical Latin pathologia "study of disease," from Greek pathos "suffering" (see pathos) + -logia "study" (see -logy). In reference to the study of abnormal mental conditions from 1842. Ancient Greek pathologia was "study of the passions;" the Greek word for "science of diseases" was pathologike ("pathologics").
pathophysiology (adj.): 1952, from patho- + physiology.
pathos (n.): "quality that arouses pity or sorrow," 1660s, from Greek pathos "suffering, feeling, emotion, calamity," literally "what befalls one," related to paskhein "to suffer," and penthos "grief, sorrow;" from PIE root *kwent(h)- "to suffer, endure" (source also of Old Irish cessaim "I suffer," Lithuanian kenčiu "to suffer," pakanta "patience").
pathway (n.): 1530s, from path + way (n.). An etymological tautology.
patience (n.): c. 1200, "quality of being willing to bear adversities, calm endurance of misfortune, suffering, etc.," from Old French pacience "patience; sufferance, permission" (12c.) and directly from Latin patientia "patience, endurance, submission," also "indulgence, leniency; humility; submissiveness; submission to lust;" literally "quality of suffering." It is an abstract noun formed from the adjective patientem (nominative patiens) "bearing, supporting; suffering, enduring, permitting; tolerant," but also "firm, unyielding, hard," used of persons as well as of navigable rivers, present participle of pati "to suffer, endure," from PIE root *pe(i)- "to damage, injure, hurt" (see passion).
Patience, n. A minor form of despair, disguised as a virtue. [Ambrose Bierce, "Devil's Dictionary," 1911]
Meaning "constancy in effort" is attested from 1510s. Meaning "card game for one person" is from 1816.
patient (adj.): mid-14c., "enduring without complaint," from Old French pacient and directly from Latin patientem "bearing, supporting, suffering, enduring, permitting" (see patience). Meaning "pertaining to a medical patient" is late 14c., from the noun. Related: Patiently.
patient (n.): "suffering or sick person under medical treatment," late 14c., from Old French pacient (n.), from the adjective, from Latin patientem (see patience).
patina (n.): "greenish film on old bronze," 1748, from French patine (18c.), from Italian patina, perhaps from Latin patina "dish, pan" (see pan (n.)), on the notion of encrustation on ancient bronze dishes. Sense of "refinement, cultural sophistication" first recorded 1933.
patio (n.): 1818, "inner court open to the sky," from Spanish patio probably from Old Provençal patu, pati "untilled land, communal pasture," from Latin pactum "agreement" (see pact). Another theory traces the Spanish word to Latin patere "to lie open." Meaning "paved and enclosed terrace beside a building" first recorded 1941. Patio furniture is attested from 1969.
patisserie (n.): 1784, from French pâtisserie "pastry shop," from pâtisser "pastry-seller, pastry-cook," from Old French pasticier (14c.), from Medieval Latin pasticium "pasty, composed of paste," from Late Latin pasta "paste, pastry cake" (see pasta).
patois (n.): "a provincial dialect," 1640s, from French patois "native or local speech" (13c.), of uncertain origin, probably from Old French patoier "handle clumsily, to paw," from pate "a paw," from Vulgar Latin *patta (see patten), from notion of clumsy manner of speaking. Compare French pataud "properly, a young dog with big paws, then an awkwardly built fellow" [Brachet]. Especially in reference to Jamaican English from 1934.
patootie (n.): "sweetheart, pretty girl," colloquial American English, 1921, perhaps a corruption of potato (c.f. sweet potato). Sweet patootie is recorded from 1919 as a generic exclamation.
patri-: word-forming element used to make terms describing kinship of the father or the paternal line, from Latin patri-, comb. form of pater (see father (n.)).
patriarch (n.): late 12c., from Old French patriarche "one of the Old Testament fathers" (11c.) and directly from Late Latin patriarcha (Tertullian), from Greek patriarkhes "chief or head of a family," from patria "family, clan," from pater "father" (see father (n.)) + arkhein "to rule" (see archon). Also used as an honorific title of certain bishops in the early Church, notably those of Antioch, Alexandria, and Rome.
patriarchal (adj.): mid-15c., "pertaining to a (Church) patriarch," from patriarch + -al, or else from Late Latin patriarchalis, from patriarcha.
patriarchy (n.): 1560s, in ecclesiastical sense, from Greek patriarkhia, from patriarkhes (see patriarch). Meaning "system of society or government by fathers or elder males of the community" first recorded 1630s.
patriate (v.): 1966, in Canadian English (perhaps coined by Lester B. Pearson) in reference to constitutional laws, probably a back-formation from repatriate. Related: Patriated; patriation.
Patricia: fem. proper name, from Latin, fem. of patricius "patrician, noble" (see Patrick).
patrician (n.): early 15c., "member of the ancient Roman noble order," from Middle French patricien, from Latin patricius "of the rank of the nobles, of the senators; of fatherly dignity," from patres conscripti "Roman senators," literally "fathers," plural of pater "father" (see father (n.)). Contrasted, in ancient Rome, with plebeius. Applied to noble citizens and higher orders of free folk in medieval Italian and German cities (sense attested in English from 1610s); hence "nobleman, aristocrat" in a modern sense (1630s). As an adjective, attested from 1610s, from the noun.
patricide (n.): 1. "person who kills his father" (1590s), 2. "act of killing one's father" (1620s), from Middle French patricide in both senses, from 1. Latin patricida "murderer of a father," 2. Latin patricidium, from pater "father" + 1. cida "killer," 2. cidium "killing" (see -cide).
Patrick: masc. proper name, from Old Irish Patraicc (Irish Padraig), from Latin Patricius, literally "a patrician" (see patrician). As a given name, chiefly in northern England and Scotland, in Ireland only a popular name after 1600, due probably to the Scots settlers in Ulster. [Reaney]
patrilineal (adj.): 1904, from patri- + lineal.
patrilocal (adj.): 1906, from patri- + local (adj.).
patrimonial (adj.): 1520s, from Middle French patrimonial- and directly from Late Latin patrimonialis, from Latin patrimonium (see patrimony).
patrimony (n.): mid-14c., "property of the Church," also "spiritual legacy of Christ," from Old French patremoine "heritage, patrimony" (12c.) and directly from Latin patrimonium "a paternal estate, inheritance from a father," also figurative, from pater (genitive patris) "father" (see father (n.)) + -monium, suffix signifying action, state, condition. Meaning "property inherited from a father or ancestors" is attested from late 14c. Figurative sense of "immaterial things handed down from the past" is from 1580s. A curious sense contrast to matrimony.
patriot (n.): 1590s, "compatriot," from Middle French patriote (15c.) and directly from Late Latin patriota "fellow-countryman" (6c.), from Greek patriotes "fellow countryman," from patrios "of one's fathers," patris "fatherland," from pater (genitive patros) "father" (see father (n.)); with -otes, suffix expressing state or condition. Liddell & Scott write that patriotes was "applied to barbarians who had only a common [patris], [politai] being used of Greeks who had a common [polis] (or free-state)."

Meaning "loyal and disinterested supporter of one's country" is attested from c. 1600, but became an ironic term of ridicule or abuse from mid-18c. in England, so that Johnson, who at first defined it as "one whose ruling passion is the love of his country," in his fourth edition added, "It is sometimes used for a factious disturber of the government."
The name of patriot had become [c. 1744] a by-word of derision. Horace Walpole scarcely exaggerated when he said that ... the most popular declaration which a candidate could make on the hustings was that he had never been and never would be a patriot. [Macaulay, "Horace Walpole," 1833]
Somewhat revived in reference to resistance movements in overrun countries in World War II, it has usually had a positive sense in American English, where the phony and rascally variety has been consigned to the word patrioteer (1928). Oriana Fallaci ["The Rage and the Pride," 2002] marvels that Americans, so fond of patriotic, patriot, and patriotism, lack the root noun and are content to express the idea of patria by cumbersome compounds such as homeland. (Joyce, Shaw, and H.G. Wells all used patria as an English word early 20c., but it failed to stick.) Patriots' Day (April 19, anniversary of the 1775 skirmishes at Lexington and Concord Bridge) was observed as a legal holiday in Maine and Massachusetts from 1894.
Patriot Act: signed into law Oct. 26, 2001; a contrived acronym for Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001.
patriotic (adj.): 1650s, "of one's own country," from French patriotique or directly from Late Latin patrioticus, from Greek patriotikos, from patriotes (see patriot). Meaning "loyal, supporting one's own country" is from 1757. Related: Patriotical.
patriotism (n.): 1726, from patriot + -ism.
patristic (adj.): 1773, from patri- + -istic. Related: patristical (1819).
patroclinous (adj.): "resembling the father rather than the mother," 1913, from patri- + Greek klinein "to lean" (see lean (v.)).
patrol (n.): 1660s, "action of going the rounds" (of a military camp, etc.), from French patrouille "a night watch" (1530s), from patrouiller "go the rounds to watch or guard," originally "tramp through the mud," probably soldiers' slang, from Old French patouiller "paddle in water," probably from pate "paw, foot" (see patten). Compare paddlefoot, World War II U.S. Army slang for "infantry soldier." Meaning "those who go on a patrol" is from 1660s. Sense of "detachment of soldiers sent out to scout the countryside, the enemy, etc." is attested from 1702.
patrol (v.): 1690s, from patrol (n.) and in part from French patrouiller. Related: Patrolled; patrolling.
patrolman (n.): "police constable on a particular beat," 1841, from patrol (n.) + man (n.).