Online Etymology Dictionary

psychotherapy (n.): 1892 in modern sense, from psycho- + therapy, in model of French psychothérapie (1889). In early use also of hypnotism. Related: Psychotherapeutic.
psychotic (adj.): 1889, coined from psychosis, on the model of neurotic/neurosis, from Greek psykhe- "mind, soul" (see psyche).
psychotic (n.): "a psychotic person," 1901, from psychotic (adj.).
psychotropic (adj.): 1956, from psycho- + Greek -tropos "turning," from trepein (see trope). Hence, what "turns" the mind.
psychro-: word-forming element meaning "cold," from Latinized form of Greek psykhros "cold," from psykhrein "blow, make cool or cold," from the same root as psyche.
psychrometer (n.): "instrument to measure moisture in the atmosphere," 1749, from Latinized form of Greek psykhros "cold" + -meter.
psychrophobia (n.): 1727, from psychro- "cold" + -phobia "fear."
pt-: An initial consonant combination common in Greek; the p- is typically silent in English words that have it but pronounced in French, German, etc.
ptarmic (n.): "substance which causes sneezing," 1680s, from noun use of Latin ptarmicus, from Greek ptarmikos "causing sneezing," from ptarmos "sneeze."
ptarmigan (n.): bird of the grouse family, 1590s, from Gaelic tarmachan, of unknown origin. The pt- spelling (1680s) is a mistaken Greek construction (perhaps based on pteron "wing").
ptero-: before vowels pter-, word-forming element in science meaning "feather; wing," from Greek pteron "wing," from PIE *pt-ero- (source also of Sanskrit patram "wing, feather," Old Church Slavonic pero "pen," Old Norse fjöðr, Old English feðer), from root *pet- "to rush; to fly" (see petition (n.))
pterodactyl (n.): extinct flying reptile, 1830, from French ptérodactyle (1821), from Modern Latin genus name Pterodactylus, from Greek pteron "wing" (see ptero-) + daktylos "finger" (see dactyl).
Ptolemaic (adj.): 1670s, "of Ptolemy," Alexandrian astronomer (2c.) whose geocentric model of the universe was accepted until the time of Copernicus and Kepler. Also (1771) "of the Ptolemies," Macedonian Greek dynasty that ruled Egypt from the death of Alexander to Cleopatra. Earlier form was Ptolemaean (1640s).
Ptolemy: ancient masc. proper name, from Greek Ptolemaios, literally "warlike," from ptolemos, collateral form of polemos "war." Also see Ptolemaic.
ptomaine (n.): 1880, from Italian ptomaina, coined by Professor Francesco Selmi of Bologna, 1878, from Greek ptoma "corpse," on notion of poison produced in decaying matter. Greek ptoma is literally "a fall, a falling," via the notion of "fallen thing, fallen body;" nominal derivative of piptein "to fall" (see symptom). Incorrectly formed, and Selmi is roundly scolded for it in OED, which says proper Greek would be *ptomatine.
ptosis (n.): 1743, from Greek ptosis, literally "falling, a fall," also "the case of a noun," nominal derivative of piptein "to fall" (see symptom). In English, especially of the eyelid. Related: Ptotic.
pub (n.): 1859, slang shortening of public house (see public (adj.)), which originally meant "any building open to the public" (1570s), then "inn that provides food and is licensed to sell ale, wine, and spirits" (1660s), and finally "tavern" (1768). Pub crawl first attested 1910 in British slang.
puberty (n.): "the time of life in which the two sexes begin first to be acquainted" [Johnson], late 14c., from Old French puberté and directly from Latin pubertatem (nominative pubertas) "age of maturity, manhood," from pubes (genitive pubertis) "adult, full-grown, manly." Related: Puberal; pubertal.
pubes (n.): 1560s, "pubic hair," from Latin pubes "pubescent, arrived at the age of puberty, of ripe years, grown up," also, as a noun, "a sign of puberty" (such as pubic hair), also "young men of the age of puberty" (see puberty). In 19c. also "pubic bone," and earlier "part of either hip bone that forms the front of the pelvis," from Latin os pubis, from pubes "genital area." In modern slang, monosyllable, a familiar shortening of pubic hairs (see pubic).
pubescence (n.): early 15c., Middle French pubescence, from Medieval Latin pubescentia, noun of state from Latin pubescentem (nominative pubescens), present participle of pubescere "grow up; ripen, come to maturity; reach the age of puberty, arrive at puberty," from pubes "adult, full-grown" (see puberty).
pubescent (adj.): 1610s, a back-formation from pubescence, or else from French pubescent (early 16c.) or directly from Latin pubescentem (nominative pubescens), present participle of pubescere "to reach puberty" (see pubescence).
pubic (adj.): 1811, with -ic + medical Latin pubis "bone of the groin" (1590s), short for Latin os pubis, from Latin pubes (genitive pubis) "genital area, groin," related to pubes (adj.) "full-grown" (see puberty).
public (adj.): late 14c., "open to general observation," from Old French public (c. 1300) and directly from Latin publicus "of the people; of the state; done for the state," also "common, general, public; ordinary, vulgar," and as a noun, "a commonwealth; public property," altered (probably by influence of Latin pubes "adult population, adult") from Old Latin poplicus "pertaining to the people," from populus "people" (see people (n.)).

Early 15c. as "pertaining to the people." From late 15c. as "pertaining to public affairs;" meaning "open to all in the community" is from 1540s in English. An Old English adjective in this sense was folclic. Public relations first recorded 1913 (after an isolated use by Thomas Jefferson in 1807). Public office "position held by a public official" is from 1821; public service is from 1570s; public interest from 1670s. Public-spirited is from 1670s. Public enemy is attested from 1756. Public sector attested from 1949. Public funds (1713) are the funded debts of a government.

Public school is from 1570s, originally, in Britain, a grammar school endowed for the benefit of the public, but most have evolved into boarding-schools for the well-to-do. The main modern meaning in U.S., "school (usually free) provided at public expense and run by local authorities," is attested from 1640s. For public house, see pub.
public (n.): "the community," 1610s, from public (adj.); meaning "people in general" is from 1660s. In public "in public view, publicly" is attested from c. 1500.
publican (n.): c. 1200, "tax-gatherer," from Old French publician (12c.), from Latin publicanus "a tax collector," noun use of an adjective, "pertaining to public revenue," from publicum "public revenue," noun use of neuter of publicus (see public (adj.)). Original sense in Matt. xviii:17, etc.; meaning "keeper of a pub" first recorded 1728, from public (house) + -an.
publication (n.): late 14c., "the act of making publicly known," from Old French publicacion (14c.) and directly from Latin publicationem (nominative publicatio) "a making public," noun of action from past participle stem of publicare "make public," from publicus (see public (adj.)). Meaning "the issuing of a written or printed work" is first recorded 1570s; as the word for the thing so issued, from 1650s. Parallel publishment had a shadowy existence alongside this word, in local and specialized use, into the 18c.
publicise (v.): chiefly British English spelling of publicize. For suffix, see -ize. Related: Publicised; publicising.
publicist (n.): 1792, "person learned in public law or the law of nations," from public (adj.) + -ist. Also from 1795 in English as "writer on current topics," from French publiciste; in either case a hybrid.
Then crept in the "loose" usage. Anybody who wrote or spoke about public affairs came to be dubbed a publicist. It was only a question of time when the dam would give way and the word flow in all directions and be made to cover every kind of talent, or lack of it. ["The Nation," Nov. 22, 1917]
Meaning "press agent" is from 1925 (publicity agent attested by 1900); publicitor also was tried in this sense.
publicity (n.): 1791, "condition of being public," from French publicité (1690s), from Medieval Latin publicitatem (nominative publicitas), from Latin publicus (see public (adj.)). Sense of "a making (something) known, an exposure to the public" is from 1826, shading by c. 1900 into "advertising, business of promotion." Publicity stunt first recorded 1908.
publicization (n.): "act of publicizing," 1962, noun of action from publicize. There is a 1907 use in the sense "a making public" (of bridges built privately, etc.).
publicize (n.): 1902; see public (adj.) + -ize. Related: Publicized; publicizing.
publicly (adv.): 1560s, "in public," from public (adj.) + -ly (2). From 1580s as "by the public." Variant publically is attested from 1812, perhaps based on the fact that publicly is the only exception in this class of words, which as a rule are spelled -ically though often they are pronounced otherwise.
publish (v.): mid-14c., "make publicly known, reveal, divulge, announce;" alteration of publicen (early 14c.) by influence of banish, finish, etc.; from extended stem of Old French publier "make public, spread abroad, communicate," from Latin publicare "make public," from publicus "public" (see public). Meaning "issue (a book, etc.) to the public" is from late 14c., also "to disgrace, put to shame; denounce publicly." Related: Published; publishing. In Middle English the verb also meant "to people, populate; to multiply, breed" (late 14c.), for example ben published of "be descended from."
publishable (adj.): 1803, from publish + -able.
publisher (n.): mid-15c., "one who announces in public," agent noun from publish (v.). Meaning "one whose business is bringing out for sale books, periodicals, engravings, etc." is from 1740.
publishing (n.): mid-15c., "act of announcing or declaring," also "the issuing of copies of a book for public sale," verbal noun from publish (v.).
puce (n.): "brownish-purple," 1787, from French puce "flea-color; flea," from Latin pucilem (nominative pulex) "flea," from PIE *plou- "flea" (source also of Sanskrit plusih, Greek psylla, Old Church Slavonic blucha, Lithuanian blusa, Armenian lu "flea"). That it could be generally recognized as a color seems a testimony to our ancestors' intimacy with vermin.
pucelle (n.): "maid," mid-15c., especially in reference to Joan of Arc (called in Old French la pucelle from c. 1423), according to French sources from Vulgar Latin *pulicella "maid" (source also of Italian pulcella), diminutive of Latin pulla, fem. of pullus "young animal," especially a chicken (see foal (n.)), but there are difficulties with this derivation. Also, in 16c. English, "a drab, a slut."
puck (n.): "ice hockey disk," 1891, possibly from puck (v.) "to hit, strike" (1861), which perhaps is related to poke (v.) via notion of "push." Another suggestion traces the noun to Irish poc "bag."
Puck: "mischievous fairy" (in "A Midsummer Night's Dream"), probably from pouke "devil, evil spirit" (c. 1300), from Old English puca, pucel "goblin," cognate with Old Norse puki "devil, fiend," of unknown origin (compare pug). Celtic origins also have been proposed. Capitalized since 16c. His disguised name was Robin Goodfellow.
pucker (v.): 1590s, "prob. earlier in colloquial use" [OED], possibly a frequentative form of pock, dialectal variant of poke "bag, sack" (see poke (n.1)), which would give it the same notion as in purse (v.). "Verbs of this type often shorten or obscure the original vowel; compare clutter, flutter, putter, etc." [Barnhart]. Related: Puckered; puckering.
pucker (n.): 1726, literal; 1741, figurative; from pucker (v.).
puckish (adj.): 1867, from Puck + -ish. Related: Puckishly; puckishness.
puckster (n.): headlinese for "ice hockey player," 1939, from puck (n.) + -ster.
pud (n.): slang for "penis," 1939 (in James Joyce), according to OED and DAS from pudding in the same slang sense (1719); from the original "sausage" sense of pudding (q.v.).
pudding (n.): c. 1300, "a kind of sausage: the stomach or one of the entrails of a pig, sheep, etc., stuffed with minced meat, suet, seasoning, boiled and kept till needed," perhaps from a West Germanic stem *pud- "to swell" (source also of Old English puduc "a wen," Westphalian dialect puddek "lump, pudding," Low German pudde-wurst "black pudding," English dialectal pod "belly;" also see pudgy).

Other possibility is the traditional one that it is from Old French boudin "sausage," from Vulgar Latin *botellinus, from Latin botellus "sausage" (change of French b- to English p- presents difficulties, but compare purse (n.)). The modern sense had emerged by 1670, from extension to other foods boiled or steamed in a bag or sack (16c.). German pudding, French pouding, Swedish pudding, Irish putog are from English. Pudding-pie attested from 1590s.
puddinghead (n.): "amiable stupid person," 1851, from pudding + head (n.).
puddle (n.): early 14c., "small pool of dirty water," frequentative or diminutive of Old English pudd "ditch," related to German pudeln "to splash in water" (compare poodle). Originally used of pools and ponds as well.
puddle (v.): "to dabble in water, poke in mud," mid-15c., from puddle (n.); extended sense in iron manufacture is "turn and stir (molten iron) in a furnace." Related: Puddled; puddling.
pudendum (n.): "external genitals," late 14c. (pudenda), from Latin pudendum (plural pudenda), literally "thing to be ashamed of," neuter gerundive of pudere "make ashamed; be ashamed," from PIE root *(s)peud- "to punish, repulse." Translated into Old English as scamlim ("shame-limb"); in Middle English also Englished as pudende (early 15c.). Related: Pudendal.