Online Etymology Dictionary

practically (adv.): 1620s, "in a practical manner," from practical + -ly (2). Meaning "for practical purposes, as good as" is from 1748; loosened sense of "almost" is from 1869.
practice (v.): c. 1400, "to do, act;" early 15c., "to follow or employ; to carry on a profession," especially medicine, from Old French pratiser, practiser "to practice," alteration of practiquer, from Medieval Latin practicare "to do, perform, practice," from Late Latin practicus "practical," from Greek praktikos "practical" (see practical).

From early 15c. as "to perform repeatedly to acquire skill, to learn by repeated performance;" mid-15c. as "to perform, to work at, exercise." Related: Practiced; practicing.
practice (n.): early 15c., practise, "practical application," originally especially of medicine but also alchemy, education, etc.; from Old French pratiser, from Medieval Latin practicare (see practice (v.)). From early 15c. often assimilated in spelling to nouns in -ice. Also as practic, which survived in parallel into 19c.
practiced (adj.): "expert," 1560s, past participle adjective from practice (v.).
practicing (adj.): 1620s in reference to professions; from 1906 in reference to religions; present participle adjective from practice (v.).
practicum (n.): 1904, from Late Latin practicum, neuter of practicus (see practical). Compare German praktikum.
practise: chiefly British English spelling of practice.
practitioner (n.): 1540s, a hybrid formed from practitian "practitioner" (c. 1500, from French practicien, from Late Latin practicus "fit for action," see practice (v.)) on model of parishioner. Johnson has as a secondary sense "One who uses any sly or dangerous arts."
Prado (n.): public park and promenade in Madrid, 1640s, Spanish, from Latin pratum "meadow" (see prairie). Compare Prater, large park in Vienna, German, from Italian prato "meadow." French preau "little meadow," formerly praël, Italian pratello are from Vulgar Latin *pratellum, diminutive of pratum.
prae-: word-forming element meaning "before," from Latin prae (adv.) "before," from PIE *prai-, *prei-, from root *per- (1) "forward, through" (see per; also see pre-). Reduced to pre- in Medieval Latin. According to OED the full form prae- in Modern English appears "usually only in words that are still regarded as Latin, ... or that are terms of classical antiquity ...."
praecipe (n.): c. 1500 (in Magna Carta in Anglo-Latin), from Latin praecipe, imperative of praecipere "to admonish, enjoin," from the opening words of such a writ, praecipe quod reddat "enjoin (him) that he render."
praenomen (n.): from Latin praenomen, literally "before the name," from prae- (see pre-) + nomen (see name (n.)).
Praesepe (n.): loose ("open") star cluster (M44) in Cancer, from Latin praesaepe the Roman name for the grouping, literally "enclosure, stall, manger, hive," from prae- (see pre-) + saepire "to fence" (see septum).

It is similar to the Hyades but more distant, about 600 light-years away, consists of about 1,000 stars, mostly older, the brightest of them around magnitude 6.5, thus not discernible to the naked eye even on the clearest nights, but their collective light makes a visible fuzz of glow that the ancients likened to a cloud (the original nebula); Galileo was the first to resolve it into stars (1609). The modern name for it in U.S. and Britain, Beehive, seems no older than 1840. Greek names included Nephelion "Little Cloud" and Akhlys "Little Mist." "In astrology, like all clusters, it threatened mischief and blindness" [Allen].

"Manger" to the Romans perhaps by influence of two nearby stars, Gamma and Delta Cancri, dim and unspectacular but both for some reason figuring largely in ancient astrology and weather forecasting, and known as "the Asses" (Latin Aselli), supposedly those of Silenus.
praeter-: see preter-.
praetor (n.): elected magistrate in ancient Rome (subordinate to consuls), early 15c., from Latin praetor "one who goes before;" originally "a consul as leader of an army," from prae "before" (see pre-) + root of ire "to go" (see ion).
Praetorian (adj.): early 15c., from Latin praetorianus "belonging to a praetor," from praetor (see praetor). Praetorian Guard is from cohors praetoria, the bodyguard troop of a Roman commander or emperor. Hence modern figurative use for "defenders of an existing order."
pragmatic (adj.): 1610s, "meddlesome, impertinently busy," short for earlier pragmatical, or else from Middle French pragmatique (15c.), from Latin pragmaticus "skilled in business or law," from Greek pragmatikos "fit for business, active, business-like; systematic," from pragma (genitive pragmatos) "a deed, act; that which has been done; a thing, matter, affair," especially an important one; also a euphemism for something bad or disgraceful; in plural, "circumstances, affairs" (public or private), often in a bad sense, "trouble," literally "a thing done," from stem of prassein/prattein "to do, act, perform" (see practical). Meaning "matter-of-fact" is from 1853. In some later senses from German pragmatisch.
pragmatical (adj.): 1590s, "concerned with practical results," from Latin pragmaticus (see pragmatic) + -al (1). Related: Pragmatically.
pragmaticism (n.): 1865, "officiousness," from pragmatic + -ism. From 1905 as a term in philosophy by American philosopher C.S. Peirce (1839-1914).
pragmatism (n.): "matter-of-fact treatment," 1825, from Greek pragmat-, stem of pragma "that which has been done" (see pragmatic) + -ism. As a philosophical doctrine, 1898, said to be from 1870s; probably from German Pragmatismus. As a name for a political theory, from 1951. Related: Pragmatist (1630s as "busybody;" 1892 as "adherent of a pragmatic philosophy").
Prague: capital of the Czech Republic, Czech Praha, perhaps from an ancient Slavic word related to Czech pražiti, a term for woodland cleared by burning. Popular etymology is from Czech prah "threshold." Related: Praguean; Praguian.
prairie (n.): tract of level or undulating grassland in North America, by 1773, from French prairie "meadow, grassland," from Old French praerie "meadow, pastureland" (12c.), from Vulgar Latin *prataria, from Latin pratum "meadow," originally "a hollow." The word existed in Middle English as prayere, but was lost and reborrowed to describe the American plains. Prairie dog is attested from 1774; prairie schooner "immigrant's wagon" is from 1841. Illinois has been the Prairie State since at least 1861. In Latin, Neptunia prata was poetic for "the sea."
praise (v.): c. 1300, "to laud, commend, flatter," from Old French preisier, variant of prisier "to praise, value," from Late Latin preciare, earlier pretiare (see price (n.)). Replaced Old English lof, hreþ.

Specifically with God as an object from late 14c. Related: Praised; praising. Now a verb in most Germanic languages (German preis, Danish pris, etc.), but only in English is it differentiated in form from cognate price.
praise (n.): early 14c., not common until 16c., from praise (v.).
praiseworthy (adj.): mid-15c., from praise (v.) + worthy. Usually hyphenated until mid-19c. Related: Praiseworthiness.
Prakrit (n.): popular dialect of ancient northern and central India (distinguished from Sanskrit), sometimes also applied to modern languages, 1766, from Sanskrit prakrta- "natural, original" (opposed to samskrta- "prepared, refined"), from pra- "before, forward, forth" (see pro-) + krta- "to make, do, perform," from PIE root *k(w)er- "to make, form" (related to karma).
praline (n.): 1727, prawlin, from French praline (17c.), from the name of Marshal Duplessis-Praslin (1598-1675, pronounced "praline"), "whose cook invented this confection" [Klein]. Modern spelling in English from 1809.
pram (n.): "baby carriage," 1881, shortening of perambulator, perhaps influenced by pram "flat-bottomed boat" especially a type used in the Baltic (1540s), from Old Norse pramr, from Balto-Slavic (compare Polish prom, Russian poromu "ferryboat," Czech pram "raft"), from PIE *pro-, from root *per- (1) "forward, through" (see per).
prance (v.): late 14c., originally of horses, of unknown origin, perhaps related to Middle English pranken "to show off," from Middle Dutch pronken "to strut, parade" (see prank); or perhaps from Danish dialectal prandse "to go in a stately manner." Klein suggests Old French paravancier. Related: Pranced; prancing. As a noun from 1751, from the verb.
prancer (n.): 1560s, originally thieves' slang for "a horse," agent noun from prance (v.).
prandial (adj.): "pertaining to dinner," 1820, from Latin prandium "late breakfast, luncheon" (see postprandial). OED reports it as "affected or jocose."
prank (n.): "a ludicrous trick" [Johnson], 1520s, of uncertain origin, perhaps related to obsolete verb prank "decorate, dress up" (mid-15c.), related to Middle Low German prank "display" (compare also Dutch pronken, German prunken "to make a show, to strut"). The verb in the modern sense also is from 1520s. Related: Pranked; pranking.
prankster (n.): 1927, American English, from prank + -ster.
praseodymium (n.): rare metallic element, 1885, coined in Modern Latin by discoverer Carl Auer von Welsbach (1858-1929) from Greek prasios "leek-green" (from prason "leek") + didymos "double," the name given to an earth in 1840, so called because it was a "twin" to lanthana. When didymia was further analyzed in the 1880s, it was found to have several components, one of which was characterized by green salts and named accordingly, with the elemental suffix -ium.
prat (n.): "buttock," 1560s, criminals' slang, of unknown origin. Later in U.S. criminal slang, "hip pocket" (1914), and in British slang "contemptible person" (1968).
prate (v.): early 15c., from or related to Middle Dutch praten "to chatter" (c. 1400), from a Proto-Germanic imitative root (compare East Frisian proten, Middle Low German praten, Middle High German braten, Swedish prata "to talk, chatter"). Related: Prated; prating. As a noun from 1570s.
pratfall (n.): 1939, from prat "buttock" + fall (n.). "Chiefly N. Amer. slang" [OED]. As a verb from 1940.
Pratt: the surname apparently is from Old English *prætt (adj.) "cunning, astute;" related to late Old English noun prætt "a trick" (see pretty). As a type of pottery, named for Staffordshire pottery manufacturer Felix Pratt (1780-1859).
prattle (v.): 1530s, frequentative of prate (q.v.). Related: Prattled; prattling. The noun is attested from 1550s.
pravity (n.): "depravity," 1540s, from Latin pravitas "crookedness, distortion, deformity; impropriety, perverseness," from pravus "wrong, bad," literally "crooked."
prawn (n.): early 15c., prayne, of unknown origin. "No similar name found in other langs." [OED].
praxis (n.): 1580s, from Medieval Latin praxis "practice, exercise, action" (mid-13c., opposite of theory), from Greek praxis "practice, action, doing," from stem of prassein, prattein "to do, to act" (see practical).
pray (v.): early 13c., "ask earnestly, beg," also (c. 1300) "pray to a god or saint," from Old French preier "to pray" (c.900, Modern French prier), from Vulgar Latin *precare (also source of Italian pregare), from Latin precari "ask earnestly, beg, entreat," from *prex (plural preces, genitive precis) "prayer, request, entreaty," from PIE root *prek- "to ask, request, entreat" (source also of Sanskrit prasna-, Avestan frashna- "question;" Old Church Slavonic prositi, Lithuanian prasyti "to ask, beg;" Old High German frahen, German fragen, Old English fricgan "to ask" a question).

Parenthetical expression I pray you, "please, if you will," attested from 1510s, contracted to pray 16c. Related: Prayed; praying. Praying mantis attested from 1809. The "Gardener's Monthly" of July 1861 lists other names for it as camel cricket, soothsayer, and rear horse.
prayer (n.): c. 1300, from Old French prier "prayer, petition, request" (12c., Modern French prière), from Medieval Latin precaria "petition, prayer," noun use of Latin adjective precaria, fem. of precarius "obtained by prayer, given as a favor," from precari "to ask, beg, pray" (see pray). Related: Prayers.

Prayer-book attested from 1590s; prayer-meeting from 1780. To not have a prayer "have no chance" is from 1941.
prayerful (adj.): 1620s, from prayer + -ful. Related: Prayerfully; prayerfulness.
pre-: word-forming element meaning "before," from Old French pre- and Medieval Latin pre-, both from Latin prae (adverb and preposition) "before in time or place," from PIE *peri- (source also of Oscan prai, Umbrian pre, Sanskrit pare "thereupon," Greek parai "at," Gaulish are- "at, before," Lithuanian pre "at," Old Church Slavonic pri "at," Gothic faura, Old English fore "before"), extended form of root *per- (1) "beyond, forward, through" (see per).

The Latin word was active in forming verbs. Also see prae-. Sometimes in Middle English muddled with words in pro- or per-.
pre-arrange (v.): also prearrange, 1792 (implied in pre-arranged), from pre- + arrange. Related: Pre-arranging.
pre-arrangement (n.): also prearrangement, 1775, from pre- + arrangement.
pre-atomic (adj.): "before the atomic age," 1914, in "World Set Free" -- H.G. Wells anticipating the word the future would use to look back at a time defined by events that hadn't yet happened in his day; from pre- + atomic.
pre-date (v.): also predate, 1859, "to antedate, to assign an earlier date to," from pre- + date (n.1) "point in time." As "to exist before," from 1857. Related: Pre-dated; pre-dating.