Online Etymology Dictionary

prettily (adv.): early 15c., from pretty (adj.) + -ly (2).
prettiness (n.): 1520s, from pretty + -ness.
pretty (adj.): Old English prættig (West Saxon), pretti (Kentish), *prettig (Mercian) "cunning, skillful, artful, wily, astute," from prætt, *prett "a trick, wile, craft," from Proto-Germanic *pratt- (source also of Old Norse prettr "a trick," prettugr "tricky;" Frisian pret, Middle Dutch perte, Dutch pret "trick, joke," Dutch prettig "sportive, funny," Flemish pertig "brisk, clever"), of unknown origin.

Connection between Old English and Middle English words is uncertain, but if they are the same, meaning had shifted by c. 1400 to "manly, gallant," and later moved via "attractive, skillfully made," to "fine," to "beautiful in a slight way" (mid-15c.). Ironical use from 1530s. For sense evolution, compare nice, silly. Also used of bees (c. 1400). "After the OE. period the word is unknown till the 15th c., when it becomes all at once frequent in various senses, none identical with the OE., though derivable from it" [OED].

Meaning "not a few, considerable" is from late 15c. With a sense of "moderately," qualifying adjectives and adverbs, since 1560s. Pretty please as an emphatic plea is attested from 1902. A pretty penny "lot of money" is first recorded 1768.
pretty (v.): 1916, usually with up, from pretty (adj.). Related: Prettied; prettying. Compare prettify.
pretty (n.): "a pretty person or thing," 1736, from pretty (adj.).
pretty-boy: 1885 as an adjective, 1888 as a noun, from pretty (adj.) + boy (n.). In Middle English a pretty man was "a worthy or clever fellow."
pretzel (n.): 1851, from German Prezel, also Brezel, from Middle High German brezel, prezel, from Old High German brezitella, brecedela, from Medieval Latin *brachitella, presumably a kind of biscuit baked in the shape of folded arms (source also of Italian bracciatella, Old Provençal brassadel), diminutive of Latin bracchiatus "with branches, with arms," from bracchium "an arm, a forearm," from Greek brakhion "an arm" (see brachio-).
prevail (v.): c. 1400, "be successful; be efficacious," from Old French prevaleir (Modern French prévaloir) and directly from Latin praevalere "be stronger, have greater power," from prae "before" (see pre-) + valere "have power, be strong" (see valiant). Spelling in English perhaps influenced by avail. Related: Prevailed; prevailing.
prevailing (adj.): 1590s, "vigorous;" 1680s, "widely accepted," present participle adjective from prevail (v.).
prevalence (n.): 1590s, "fact of having mastery," from Middle French prévalence (15c.), from Late Latin praevalentia, from praevalens, present participle of praevalere (see prevalent). Meaning "condition of being widespread or general" is from 1713.
prevalent (adj.): early 15c., "having great power or force," from Latin praevalentem (nominative praevalens) "of superior strength; mighty," present participle of praevalere "to be more able" (see prevail). Meaning "extensively existing, in general use" is from 1650s.
prevaricate (v.): 1580s, "to transgress," a back formation from prevarication, or else from Latin praevaricatus, past participle of praevaricari "to make a sham accusation, deviate," literally "walk crookedly;" in Church Latin, "to transgress" (see prevarication). Meaning "to speak evasively" is from 1630s. Related: Prevaricated; prevaricating.
prevarication (n.): late 14c., "divergence from a right course, transgression," from Old French prevaricacion "breaking of God's laws, disobedience (to the Faith)" (12c., Modern French prévarication) and directly from Latin praevaricationem (nominative praevaricatio) "duplicity, collusion, a stepping out of line (of duty or behavior)," noun of action from past participle stem of praevaricari "to make a sham accusation, deviate," literally "walk crookedly," in Church Latin, "to transgress," from prae "before" (see pre-) + varicare "to straddle," from varicus "straddling," from varus "bowlegged, knock-kneed" (see varus). Meaning "evasion, quibbling" is attested from 1650s.
prevaricator (n.): c. 1400, from Old French prevaricator and directly from Latin praevaricator "sham accuser; unfaithful advocate," agent noun from past participle stem of praevaricari (see prevaricate).
prevenient (adj.): 1650s, from Latin praevenientem (nominative praeveniens), present participle of praevenire, from prae- (see pre-) + venire "to come" (see venue).
prevent (v.): early 15c., "act in anticipation of," from Latin praeventus, past participle of praevenire "come before, anticipate, hinder," in Late Latin also "to prevent," from prae "before" (see pre-) + venire "to come" (see venue). Originally literal; sense of "anticipate to hinder" was in Latin, but not recorded in English until 1540s.
preventable (adj.): 1630s, from prevent + -able.
preventative (adj.): 1650s, from prevent + -ative. OED points out that preventive is better-formed. As a noun, from 1774.
prevention (n.): mid-15c., "action of stopping an event or practice," from Middle French prévention and directly from Late Latin praeventionem (nominative praeventio) "action of anticipating," noun of action from past participle stem of praevenire (see prevent).
preventive (adj.): 1630s, from Latin praevent-, past participle stem of praevenire (see prevent), + -ive. As a noun, from 1630s; in medical use from 1670s.
preverbal (adj.): 1931, from pre- + verbal.
preview (v.): c. 1600, "to see beforehand," from pre- + view (v.). Meaning "to show (a film, etc.) before its public opening" is from 1928. Related: Previewed; previewing.
preview (n.): "a foretaste," 1880, from preview (v.); specifically "a showing of a book, film, etc. before public release" from 1920.
previous (adj.): 1620s, from Latin praevius "going before," from prae "before" (see pre-) + via "road" (see via). Related: Previously.
prevision (n.): 1610s, "foresight," from French prévision (14c.), from Late Latin praevisionem (nominative praevisio), noun of action from past participle stem of Latin praevidere "see first, see beforehand," from prae- "before" (see pre-) + videre "to see" (see vision).
prex (n.): U.S. college slang for president (of a college), 1828. As a Latin verb, it meant "a request, entreaty."
prexy (n.): 1871, slang extension of prex.
prey (n.): mid-13c., "animal hunted for food," also "that which is taken in war," from Old French preie "booty, animal taken in the chase" (mid-12c., Modern French proie), from Latin praeda "booty, plunder, game hunted," earlier praeheda, literally "something seized before," from PIE *prai-heda-; for first element see prae-; second element related to the second element in prehendere "to grasp, seize" (see prehensile).
prey (v.): c. 1300, "to plunder, pillage, ravage," from prey (n.) and in part from Old French preer, earlier preder (c.1040), from Late Latin praedare, from praeda (see prey (n.)). Its sense of "to kill and devour" is attested from mid-14c. Related: Preyed; preying.
prez (n.): slang shortening of president, 1892, American English. Compare prex.
priapic (adj.): "phallic," 1786, with -ic + Priapus (Greek Priapos), son of Dionysus and Aphrodite, the god who personified male reproductive power. His name is of unknown origin.
priapism (n.): "persistent erection of the penis," 1620s, from Late Latin priapismus, from Greek priapismos, from priapizein, from Priapos (see priapic + -ism).
price (n.): c. 1200, pris "value, worth; praise," later "cost, recompense, prize" (mid-13c.), from Old French pris "price, value, wages, reward," also "honor, fame, praise, prize" (Modern French prix), from Late Latin precium, from Latin pretium "reward, prize, value, worth," from PIE *pret-yo-, from root *per- (5) "to traffic in, to sell" (source also of Sanskrit aprata "without recompense, gratuitously;" Greek porne "prostitute," originally "bought, purchased," pernanai "to sell;" Lithuanian perku "I buy").

Praise, price, and prize began to diverge in Old French, with praise emerging in Middle English by early 14c. and prize being evident by late 1500s with the rise of the -z- spelling. Having shed the extra Old French and Middle English senses, the word now again has the base sense of the Latin original. To set (or put) a price on someone, "offer a reward for capture" is from 1766.
price (v.): "to set the price of," late 14c., from price (n.) or from Old French prisier, variant of preisier "to value, estimate; to praise." Related: Priced; pricing.
price-tag (n.): 1881, from price (n.) + tag (n.).
priceless (adj.): "having a value beyond price," 1590s, from price (n.) + -less. Colloquial sense of "delightful" attested from 1907. Related: Pricelessly; pricelessness.
pricey (adj.): also pricy, "expensive," 1932, from price (n.) + -y (2).
prick (n.): Middle English prikke, from Old English prica (n.) "point, puncture; particle, small portion of space or time," common Proto-Germanic (compare Low German prik "point," Middle Dutch prick, Dutch prik, Swedish prick "point, dot"). Meaning "pointed weapon, dagger" is first attested 1550s.

Earliest recorded use for "penis" is 1590s (Shakespeare puns upon it). My prick was used 16c.-17c. as a term of endearment by "immodest maids" for their boyfriends. As a term of abuse, it is attested by 1929. Prick-teaser attested from 1958. The use in kick against the pricks (Acts ix:5, first in the translation of 1382) probably is from sense of "a goad for oxen" (mid-14c.), which made it a plausible translation of Latin stimulus; advorsum stimulum calces was proverbial in Latin.
prick (v.): Old English prician "to prick, pierce, prick out, sting," from West Germanic *prikojan (source also of Low German pricken, Dutch prikken "to prick"), of uncertain origin. Danish prikke "to mark with dots," Swedish pricka "to point, prick, mark with dots" probably are from Low German. Related: Pricked; pricking. To prick up one's ears is 1580s, originally of animals with pointed ears (prycke-eared, of foxes, is from 1520s).
prickle (n.): Old English pricel "thing to prick with, goad, point," from the same source as Old English prician (see prick (v.)) with instrumental suffix -el (1). Compare Middle Low German prickel, Dutch prikkel.
prickly (adj.): 1570s, "spiny, armed with prickles" (originally of holly leaves), from prickle (n.) + -y (2). Figurative sense of "irritable" first recorded 1862. Prickly heat is from 1736, so called for the sensation; prickly pear is from 1760 (earlier prickle pear, 1610s). Related: Prickliness.
pride (n.): late Old English pryto, Kentish prede, Mercian pride "pride, haughtiness, pomp," from prud (see proud). There is debate whether Scandinavian cognates (Old Norse pryði, Old Swedish prydhe , Danish pryd, etc.) are borrowed from Old French (from Germanic) or from Old English. Meaning "that which makes a person or people most proud" is from c. 1300. First applied to groups of lions late 15c., but not commonly so used until c. 1930. Paired with prejudice from 1610s.
pride (v.): mid-12c. in the reflexive sense "congratulate (oneself), be proud," c. 1200 as "be arrogant, act haughtily," from pride (n.). Related: Prided; priding.
prideful (adj.): c. 1500, from pride (n.) + -ful. Related: Pridefully; pridefulness. Old English had prutswongor "overburdened with pride."
prier (n.): "one who pries," 1550s, agent noun from pry.
priest (n.): Old English preost probably shortened from the older Germanic form represented by Old Saxon and Old High German prestar, Old Frisian prestere, all from Vulgar Latin *prester "priest," from Late Latin presbyter "presbyter, elder," from Greek presbyteros (see Presbyterian).

An alternative theory (to account for the -eo- of the Old English word) makes it cognate with Old High German priast, prest, from Vulgar Latin *prevost "one put over others," from Latin praepositus "person placed in charge," from past participle of praeponere (see provost). In Old Testament sense, a translation of Hebrew kohen, Greek hiereus, Latin sacerdos.
priestcraft (n.): late 15c., "business of being a priest," from priest + craft (n.). After rise of Protestantism and the Enlightenment, it acquired a pejorative sense of "arts and devices of ambitious priests for attaining and holding temporal power and social control" (1680s).
priestess (n.): 1690s, from priest + -ess. Earlier was priestress (late 15c.).
priesthood (n.): Old English preosthad; see priest + -hood.
priestly (adj.): mid-15c.; see priest + -ly (1). Old English had preostlic, but the modern word seems to be a Middle English re-formation.