Online Etymology Dictionary

patron (n.): "a lord-master, a protector," c. 1300, from Old French patron "patron, protector, patron saint" (12c.) and directly from Medieval Latin patronus "patron saint, bestower of a benefice, lord, master, model, pattern," from Latin patronus "defender, protector, former master (of a freed slave); advocate," from pater (genitive patris) "father" (see father (n.)). Meaning "one who advances the cause" (of an artist, institution, etc.), usually by the person's wealth and power, is attested from late 14c.; "commonly a wretch who supports with insolence, and is paid with flattery" [Johnson]. Commercial sense of "regular customer" first recorded c. 1600. Patron saint (1717) originally was simply patron (late 14c.).
patronage (n.): late 14c., "right of presenting a qualified person to a church benefice," from Old French patronage (14c.) from patron (see patron). Secular sense of "action of giving influential support" is from 1550s. General sense of "power to give jobs or favors" is from 1769; meaning "regular business of customers" is 1804.
patroness (n.): early 15c., from Medieval Latin patronissa, fem. of patronus "protector, defender" (see patron).
patronise (v.): chiefly British English spelling of patronize (q.v.); for suffix, see -ize.
patronize (v.): 1580s, "to act as a patron towards," from patron + -ize, or from Old French patroniser. Meaning "treat in a condescending way" is first attested 1797; sense of "give regular business to" is from 1801. Related: Patronized; patronizing.
patronizing (adj.): 1727, past participle adjective from patronize. Related: Patronizingly.
patronym (n.): 1834, from Greek patronymos, from patr-, comb. form of pater "father" (see father (n.)) + -onym "name" (see name (n.)).
patronymic (n.): 1610s, from Late Latin patronymicum, from neuter of patronymicus "derived from a father's name," from patronymos "named from the father," from pater (genitive patros) "father" (see father (n.)) + onyma "name," Aeolic dialectal variant of onoma "name" (see name (n.)). As an adjective from 1660s.
patroon (n.): 1660s, variant of patron used in foreign contexts, from Dutch patroon (a French loan-word) or French patron "master, patron," from Old French (see patron; also see -oon); used from 1758 in parts of New York and New Jersey colonies for "landholder," especially one with certain manorial privileges (abolished c. 1850) under the old Dutch governments by the charter of 1629.
patsy (n.): "fall guy, victim of a deception," 1903, of uncertain origin, possibly an alteration of Italian pazzo "madman" (see patch (n.2)), or south Italian dialectal paccio "fool." Another theory traces it to Patsy Bolivar, character created by Billy B. Van in an 1890s vaudeville skit who was blamed whenever anything went wrong.
"Poor Rogers," Vincent said, still smiling, "he is always the 'Patsy Bolivar' of the school."
"Yes," Frank answered, "if there are any mistakes to be made or trouble to fall into, Rogers seems to be always the victim." ["Anthony Yorke," "A College Boy," 1899]
patten (n.): late 14c., from Old French patin "clog, type of shoe" (13c.), probably from pate "paw, foot," from Gallo-Roman *pauta, ultimately perhaps imitative of the sound made by a paw. The immediate source has been sought in Celtic [Barnhart] and Germanic [OED], but evidence is wanting. Likely cognates include Provençal pauta, Catalan pote, Middle Dutch and Dutch poot, German Pfote "paw."
patter (v.1): "make quick taps," 1610s, frequentative of pat (v.). Related: Pattered; pattering. As a noun in this sense from 1844.
patter (v.2): "talk rapidly," c. 1400, from pater "mumble prayers rapidly" (c. 1300), shortened form of paternoster. Perhaps influenced by patter (v.1). The related noun is first recorded 1758, originally "cant language of thieves and beggars." Compare Devil's paternoster (1520s) "a grumbling and mumbling to oneself."
PATTERING. The maundering or pert replies of servants; also talk or palaver in order to amuse one intended to be cheated. [Grose, "Classical Dictionary of the Vulgar Tongue," 2nd edition. 1788]
pattern (n.): early 14c., "outline, plan, model, pattern;" early 15c. as "model of behavior, exemplar," from Old French patron and directly from Medieval Latin patronus (see patron).

Extended sense of "decorative design" first recorded 1580s, from earlier sense of a "patron" as a model to be imitated. The difference in form and sense between patron and pattern wasn't firm till 1700s. Meaning "model or design in dressmaking" (especially one of paper) is first recorded 1792, in Jane Austen.
pattern (v.): 1580s, "to make a pattern for, design, plan," from pattern (n.). Meaning "to make something after a pattern" is c. 1600. Phrase pattern after "take as a model" is from 1878.
patty (n.): "small pie," 1710, from patti-pan (1690s) "something baked in a small pan," from French pâté, from Old French paste (see paste (n.)).
paucity (n.): late 14c., from Old French paucité (14c.) and directly from Latin paucitatem (nominative paucitas) "fewness, scarcity, a small number," from paucus "few, little," from PIE *pau-ko-, from root *pau- (1) "few, little" (source also of Latin paullus "little;" Old English feawe "few;" see few (adj.)).
Paul: masc. proper name, Biblical name of the apostle to the Gentiles, from Latin Paulum (nominative Paulus), Roman surname of the Aemilian gens, literally "small," from PIE *pau-ro-lo-, from base *pau- (1) "few, little" (see few). Other forms include Old French Pol, Italian Paolo, Spanish Pablo, Russian Pavel.
pauldron (n.): "armor for the shoulder," mid-15c., from Old French espauleron, from espaule (French épaule) "shoulder" (see epaulet)
Pauline: fem. proper name, fem. of Paul.
Pauline (adj.): "pertaining to the apostle Paul," 1817, from Latin Paulinus, from Paulus (see Paul).
paunch (n.): late 14c. (late 12c. in surnames), from Old French pance (Old North French panche) "belly, stomach," from Latin panticem (nominative pantex) "belly, bowels" (source also of Spanish panza, Italian pancia); possibly related to panus "swelling" (see panic (n.2)).
paunchy (adj.): 1590s, from paunch + -y (2). Related: Paunchiness.
pauper (n.): 1510s, "person destitute of property or means of livelihood," from Latin pauper "poor, not wealthy, of small means" (see poor (adj.)). Originally in English a legal word, from Latin phrase in forma pauperis (late 15c.) "in the character of a poor person," thus allowed to sue in court without legal fees.
pause (n.): early 15c., from Old French pausee "a pause, interruption" (14c.) and directly from Latin pausa "a halt, stop, cessation," from Greek pausis "stopping, ceasing," from pauein "to stop, to cause to cease," from PIE root *paus- "to leave, desert, cease, stop."
pause (v.): mid-15c., from pause (n.) and from Middle French pauser, from Late Latin pausare "to halt, cease, pause," ultimately from Late Latin pausa. Related: Paused; pausing.
pavan (n.): "slow, stately dance," 1530s, from French pavane (1520s), probably from Spanish pavana, from pavo "peacock" (from Latin pavo), in reference to the bird's courting movements. But some see an Italian origin and trace the name to Padovana "Paduan." Possibly there was a merger of two distinct dance words.
pave (v.): early 14c., "to cover (a street) with stones or other material," from Old French paver "to pave" (12c.), perhaps a back-formation from Old French pavement or else from Vulgar Latin *pavare, from Latin pavire "to beat, ram, tread down," from PIE *pau- "to cut, strike, stamp" (source also of Latin putare "to prune;" Greek paiein "to strike;" Lithuanian piauju "to cut," piuklas "saw"). Related: Paved; paving. The figurative sense of "make smooth" (as in pave the way) is attested from 1580s.
pavement (n.): mid-13c., from Old French pavement "roadway, pathway; paving stone" (12c.) and directly from Latin pavimentum "hard floor, level surface beaten firm," from pavire (see pave).
paver (n.): late 15c., agent noun from pave (v.).
pavilion (n.): c. 1200, "large, stately tent," from Old French paveillon "large tent; butterfly" (12c.), from Latin papilionem (nominative papilio) "butterfly, moth," in Medieval Latin "tent" (see papillon); the type of tent so called on resemblance to wings. Meaning "open building in a park, etc., used for shelter or entertainment" is attested from 1680s.
Pavlovian (adj.): 1931, from the theories, experiments, and methods of Russian physiologist Ivan Petrovich Pavlov (1849-1936), especially in connection with the salivary reflexes of dogs in response to mental stimulus of the sound of a bell (attested from 1911, in Pavloff [sic] method).
paw (n.): c. 1300, from Old French powe, poe "paw, fist," of uncertain origin. Evidence points to a Gallo-Roman root form *pauta which probably is related to the source of patten.
paw (v.): "use the hands roughly," c. 1600, from paw (n.). Related: Pawed; pawing. Middle English had pawen "to touch or strike with the paw" (c. 1400).
pawl (n.): "bar preventing a capstan from recoiling" (nautical) 1620s, of unknown origin; perhaps from French pal "stake" [OED] or épaule "shoulder" [Klein].
pawn (n.1): "something left as security," late 15c. (mid-12c. as Anglo-Latin pandum), from Old French pan, pant "pledge, security," also "booty, plunder," perhaps from Frankish or some other Germanic source (compare Old High German pfant, German Pfand, Middle Dutch pant, Old Frisian pand "pledge"), from West Germanic *panda, of unknown origin.

The Old French word is identical to pan "cloth, piece of cloth," from Latin pannum (nominative pannus) "cloth, piece of cloth, garment" and Klein's sources feel this is the source of both the Old French and West Germanic words (perhaps on the notion of cloth used as a medium of exchange).
pawn (n.2): lowly chess piece, late 14c., from Anglo-French poun, Old French peon, earlier pehon, from Medieval Latin pedonem "foot soldier," from Late Latin pedonem (nominative pedo) "one going on foot," from Latin pes (genitive pedis) "foot," from PIE root *ped- (1) "a foot" (see foot (n.)). The chess sense was in Old French by 13c. Figurative use, of persons, is from 1580s.
pawn (v.): "to give (something) as security in exchange for," 1560s, from pawn (n.1). Related: Pawned; pawning.
pawnbroker (n.): 1680s, from pawn (n.1) + broker (n.).
Pawnee: Indian tribes of the Caddoan family, formerly inhabiting the plains of Nebraska, 1778, from Canadian French pani, from a Siouan language, such as Oto panyi.
pawnshop (n.): also pawn-shop, by 1763, from pawn (n.1) + shop (n.).
pawpaw (n.): see papaw.
pax (n.): mid-15c., "kiss of peace," from Latin pax (genitive pacis) "peace," in Ecclesiastical Latin, "kiss of peace" (see peace). Capitalized, Pax was the name of the Roman goddess of peace. Used by 1933 with adjectives from national names, on model of Pax Romana (such as Pax Britannica, 1872; Pax Americana, 1886, with reference to Latin America).
pay (v.): c. 1200, "to appease, pacify, satisfy," from Old French paier "to pay, pay up" (12c., Modern French payer), from Latin pacare "to please, pacify, satisfy" (in Medieval Latin especially "satisfy a creditor"), literally "make peaceful," from pax (genitive pacis) "peace" (see peace). Meaning "to give what is due for goods or services" arose in Medieval Latin and was attested in English by early 13c.; sense of "please, pacify" died out in English by 1500. Sense of "suffer, endure" (a punishment, etc.) is first recorded late 14c. Related: Paid; paying.
pay (n.): c. 1300, "satisfaction, liking, reward," from pay (v.), or else from Old French paie "payment, recompense," from paier. Meaning "money given for labor or services, wages" is from late 14c.
payable (adj.): late 14c., "to be paid," from pay (v.) + -able or from Old French paiable.
payback (n.): also pay-back, 1946, "net return on profits from an investment," from pay (v.) + back (adj.). Meaning "revenge" is attested from 1957.
paycheck (n.): also pay-check, 1894, from pay (n.) + check (n.1).
payday (n.): also pay-day, 1520s, from pay (n.) + day.
paydirt (n.): also pay dirt, "profit, success," 1873, from pay (n.) + dirt (n.); a word from mining, where it was used in a literal sense from 1856.