Online Etymology Dictionary

ply (v.1): "work with, use," late 14c., shortened form of applien "join to, apply" (see apply). The core of this is Latin plicare "to lay, fold, twist," from PIE root *plek- "to plait, twist" (cf. Greek plekein "to plait, twine," plektos "twisted;" Latin plectere (past participle plexus) "to plait, braid, intertwine;" Old Church Slavonic plesti "to braid, plait, twist;" Gothic flahta "braid;" Old English fleax "cloth made with flax, linen").

Sense of "travel regularly" is first 1803, perhaps from earlier sense "steer a course" (1550s). Related: Plied; plies; plying.
ply (n.): "a layer, a fold" 1530s, from Middle French pli "a fold" (13c.), alteration of Old French ploi "fold, pleat, layer" (12c.), verbal noun from ployer (later pleier) "to bend, to fold," from Latin plicare "to fold, lay" see ply (v.1)). This is the ply in plywood.
ply (v.2): "to bend," late 14c., plien, from Old French plier, earlier pleier "to fold, bend," from Latin plicare "to lay, fold, twist" (see ply (v.1)). Related: Plied; plies; plying.
Plymouth: city in Devon, England, named for its location at the mouth of the Plym River; the river is in turn named for Plympton, literally "plum-tree farm." Earlier Plymouth was Sutton Prior. The town in Massachusetts, U.S., was named 1620 by immigrants on the "Mayflower," which had sailed from Plymouth, England, and landed at what became known as Plymouth Rock.
plywood (n.): 1907, from ply (n.) + wood (n.). So called because the layers are arranged so that the grain of one runs at right angles to that of the next.
pn-: consonant sound in some English words derived from Greek. The p- typically is silent in English but pronounced in French, German, Spanish, etc.
pneuma (n.): used in English in various sense, from Greek pneuma "a blowing, a wind, blast; breeze; influence; breathed air, breath; odor, scent; spirit of a person; inspiration, a spirit, ghost," from pnein "to blow, to breathe," from PIE root *pneu- "to breathe," of imitative origin (cf. Greek pnoe "breath," pnoia "breathing;" Old English fnora "sneezing," fnæran "to snort").
pneumatic (adj.): 1650s, from Latin pneumaticus "of the wind, belonging to the air," from Greek pneumatikos "of wind or air" (which is attested mainly as "of spirit, spiritual"), from pneuma (genitive pneumatos) "the wind," also "breath" (see pneuma). Earlier was pneumatical (c.1600).
pneumatics (n.): 1650s, from pneumatic. Also see -ics.
pneumato-: before vowels pneumat-, word-forming element meaning "wind, air, spirit, presence of air," from comb. form of Greek pneuma (genitive pneumatos); see pneuma.
pneumo-: before vowels pneum-, word-forming element meaning "lung," from comb. form of Greek pneumon (see pneumonia).
pneumonia (n.): c.1600, from Modern Latin, from Greek pneumonia "inflammation of the lungs," from pneumon "lung," altered (perhaps by influence of pnein "to breathe") from pleumon "lung," literally "floater," probably cognate with Latin pulmo (see pulmonary), from PIE *pleu- "to flow, to swim" (see pluvial). Alteration in Greek perhaps by influence of pnein "to breathe."
pneumonic (adj.): "pertaining to the lungs," 1670s, from Latin pneumonicus, from Greek pneumonikos "of the lungs," from pneumon (see pneumonia).
pneumono-: before vowels pneumon-, word-forming element meaning "lung," from comb. form of Greek pneumon (genitive pneumonos "lung" (see pneumonia).
pneumonoultramicroscopicsilicovolcanoconiosis (n.): 1962, "A facetious word alleged to mean 'a lung disease caused by the inhalation of very fine silica dust' but occurring chiefly as an instance of a very long word" [OED]. Said in an early reference to have been invented by seventh grade students in Norfolk, Virginia.
pneumothorax (n.): 1821, from French pneumothorax (1803), coined by French physician Jean Marc Gaspard Itard (1774-1838) from Greek pneumon (see pneumonia) + thorax.
Po: large river in northern Italy, from Latin Padus, a name of Celtic origin.
po-face (adj.): "expressionless, impassive," 1934, American English, of unknown origin.
poach (v.1): "steal game," 1520s, "to push, poke," from Middle French pocher "to thrust, poke," from Old French pochier "poke out, gouge, prod, jab," from a Germanic source (cf. Middle High German puchen "to pound, beat, knock," German pochen, Middle Dutch boken "to beat") related to poke (v.). Sense of "trespass for the sake of stealing" is first attested 1610s, perhaps via notion of "thrusting" oneself onto another's property, or perhaps from French pocher "to pocket" (see poach (v.2)). Related: Poached; poaching.
poach (v.2): "cook in liquid," early 15c., from Old French poché, past participle of pochier (12c.), literally "put into a pocket" (as the white of an egg forms a pocket for the yolk), from poche "bag, pocket," from Frankish *pokka "bag," from Proto-Germanic *puk- (see poke (n.)). Related: Poached; poaching.
poached (adj.): of eggs, mid-15c., past participle adjective from poach (v.2).
poacher (n.): 1660s, "one who poaches game," agent noun from poach (v.1). Attested from 1846 as "vessel for poaching eggs," from poach (v.2).
Pocahontas: (c.1595-1617), daughter of Algonquian leader Powhatan, the name is said to be Algonquian Pokachantesu "she is playful."
pock (n.): Old English pocc "pustule, blister, ulcer," from Proto-Germanic *puh(h)- "to swell up, blow up" (cf. Middle Dutch pocke, Dutch pok, East Frisian pok, Low German poche, dialectal German Pfoche), from PIE root *beu- "to swell, to blow" (see bull (n.2)). Middle French pocque is from Germanic. The plural form, Middle English pokkes, is the source of pox, which since early 14c. has been used in the sense "disease characterized by pocks."
pock (v.): "to disfigure with pits or pocks," 1841. Related: Pocked; pocking.
pock-mark (n.): also pockmark, 1670s, from pock (n.) + mark (n.). As a verb from 1756. Related: Pockmarked; pock-marked.
pocket (v.): 1580s, "to place in a pocket" (often with implications of dishonesty), from pocket (n.). From the earliest use often figurative. Meaning "to form pockets" is from c.1600. Related: Pocketed; pocketing.
pocket (n.): mid-14c., pokete, "bag, pouch, small sack," from Anglo-French pokete (13c.), diminutive of Old North French poque "bag" (Old French pouche), from a Germanic source akin to Frankish *pokka "bag," from Proto-Germanic *puk- (see poke (n.)).

Meaning "small bag worn on the person, especially one sewn into a garment" is from early 15c. Sense in billiards is from 1754. Mining sense is attested from 1850; military sense of "area held by troops surrounded by the enemy" is from 1918; the general sense of "small area different than its surroundings" (1926) apparently was extended from the military use. Figuratively, "one's money" (conceived as being kept in a pocket) is from 1717. Pope Pokett (late 15c.) was figurative of the greedy and corrupt Church.
pocket (adj.): 1610s, "of or pertaining to or meant for a pocket," from pocket (n.). Pocket-knife is first recorded 1727; pocket-money is attested from 1630s. Often merely implying a small-sized version of something, e.g. of warships, from 1930, and cf. Pocket Venus "beautiful, small woman," attested from 1808. Pocket veto attested from 1842, American English.
The "pocket veto" can operate only in the case of bills sent to the President within ten days of Congressional adjournment. If he retain such a bill (figuratively, in his pocket) neither giving it his sanction by signing it, nor withholding his sanction in returning it to Congress, the bill is defeated. The President is not bound to give reasons for defeating a bill by a pocket veto which he has not had at least ten days to consider. In a regular veto he is bound to give such reasons. [James Albert Woodburn, "The American Republic and its Government," Putnam's, 1903]
pocketbook (n.): also pocket-book, 1610s, originally a small book meant to be carried in one's pocket, from pocket (n.) + book (n.). Meaning "a booklike leather folder for papers, bills, etc." is from 1722. Meaning "a woman's purse" is from 1816.
pocketful (n.): 1610s, from pocket (n.) + -ful.
poco: in musical directions, "a little, slightly," 1724, from Italian poco, from Latin paucus "few, little" (see paucity).
Pocono: mountain range and region in eastern Pennsylvania, from Delaware (Algonquian), perhaps Pocohanne "stream between mountains."
pod (n.1): "seed of beans," 1680s, of uncertain origin; found earlier in podware "seed of legumes, seed grain" (mid-15c.), which had a parallel form codware "husked or seeded plants" (late 14c.), related to cod "husk of seeded plants," which was in Old English. In reference to pregnancy from 1890; in reference to a round belly from 1825. Meaning "detachable body of an aircraft" is from 1950. Pod people (1956) is from movie "Invasion of the Body Snatchers," based on novel by Jack Finney.
pod (n.2): "herd of whales or seals," 1827, American English, of unknown origin.
podcast: 2004, noun and verb, from pod-, from iPod, brand of portable media player, + second element abstracted from broadcast. Related: Podcasting.
podgy (adj.): 1846, later collateral form of pudgy (q.v.).
podiatry (n.): 1914, formed from Greek pod-, stem of pous "foot" (see foot (n.)) + iatreia "healing," from iatros "physician" (see -iatric). An attempt to supplant chiropody (see chiropodist) and distance the practice from the popular impression of unskilled corn-cutters. The National Association of Chiropodists changed its name to American Podiatry Association in 1958. Related: Podiatric; podiatrist.
podium (n.): 1743, "raised platform around an ancient arena," also "projecting base of a pedestal," from Latin podium "raised platform," from Greek podion "foot of a vase," diminutive of pous (genitive podos) "foot" (see foot (n.)). Meaning "raised platform at the front of a hall or stage" is from 1947.
Podunk: legendary small town, 1846, originally the name of a small group of Indians who lived around the Podunk River in Connecticut; the tribe name is in colonial records from 1656 (as Potunck), from southern New England Algonquian (Mohegan or Massachusetts) Potunk, probably from pautaunke, from pot- "to sink" + locative suffix -unk, thus "a boggy place." Its popularity as the name of a typical (if mythical) U.S. small town dates from a series of witty "Letters from Podunk" which ran in the "Buffalo Daily National Pilot" newspaper beginning Jan. 5, 1846.
poem (n.): 1540s (replacing poesy in this sense), from Middle French poème (14c.), from Latin poema "composition in verse, poetry," from Greek poema "fiction, poetical work," literally "thing made or created," early variant of poiema, from poein, poiein, "to make or compose" (see poet). Spelling pome, representing an ignorant pronunciation, is attested from 1856.
poesy (n.): late 14c., "poetry; poetic language and ideas; literature; a poem, a passage of poetry," from Old French poesie (mid-14c.), from Vulgar Latin poesia (source of Provençal, Spanish, Portuguese, Italian poesia), from Latin poesis "poetry, a poem," from Greek poesis "composition, poetry," literally "a making, fabrication," variant of poiesis, from poein, poiein "to make or compose" (see poet). Meaning "the art of poetry" is late 15c.
poet (n.): early 14c., "a poet, a singer" (c.1200 as a surname), from Old French poete (12c., Modern French poète) and directly from Latin poeta "a poet," from Greek poetes "maker, author, poet," variant of poietes, from poein, poiein "to make, create, compose," from PIE *kwoiwo- "making," from root *kwei- "to pile up, build, make" (cf. Sanskrit cinoti "heaping up, piling up," Old Church Slavonic činu "act, deed, order").

Replaced Old English scop (which survives in scoff). Used in 14c., as in classical languages, for all sorts of writers or composers of works of literature. Poète maudit, "a poet insufficiently appreciated by his contemporaries," literally "cursed poet," attested by 1930, from French (1884, Verlaine). For poet laureate see laureate.
poetaster (n.): 1590s, from Middle French poetastre (1550s), from Latin poeta (see poet) + -aster, diminutive (pejorative) suffix.
poetess (n.): 1520s, from poet + -ess. Earlier fem. form was poetresse (early 15c.).
poetic (adj.): 1520s, from poet + -ic, or else from or influenced by Middle French poetique (c.1400), from Latin poeticus, from Greek poietikos "pertaining to poetry," literally "creative, productive," from poietos "made," verbal adjective of poiein "to make" (see poet). Related: Poetics (1727). Poetic justice "ideal justice as portrayed in plays and stories" is from 1670s. Poetic license attested by 1733.

Earlier adjective was poetical (late 14c.); also obsolete poetly (mid-15c.). Related: Poetically (early 15c.).
poetry (n.): late 14c., "poetry; a poem; ancient literature; poetical works, fables, or tales," from Old French poetrie (13c.), and perhaps directly from Medieval Latin poetria (c.650), from Latin poeta (see poet). In classical Latin, poetria meant "poetess."
... I decided not to tell lies in verse. Not to feign any emotion that I did not feel; not to pretend to believe in optimism or pessimism, or unreversible progress; not to say anything because it was popular, or generally accepted, or fashionable in intellectual circles, unless I myself believed it; and not to believe easily. [Robinson Jeffers (1887-1962), forward to "Selected Poems"]
Figurative use from 1660s. Old English had metergeweorc "verse," metercræft "art of versification." Modern English lacks a true verb form in this group of words, though poeticize (1804), poetize (1580s, from French poétiser), and poetrize (c.1600) have been tried. Poetry in motion (1826) perhaps is from poetry of motion (1813) "dance" (also poetry of the foot, 1660s).
pog (n.): disc used in playing a game said to have originated in Hawaii and popular in U.S. during the mid-1990s; said to be from the name of a brand of juice, the bottle caps from it being used to play the game originally.
pogo (n.): 1921, originally a registered trademark (Germany, 1919), of unknown origin, perhaps formed from elements of the names of the designers.
Hopping Stilts Are the New French Playthings. ... For France and especially Paris has taken to the "pogo" stick, a stick equipped with two rests for the feet. Inside of the stick is a strong spring so that the "pogoer" may take a series of jumps without straining his powers. The doctors claim that the jarring produced by the successive jumps do not serve to injure the spine, as one might at first suppose. This jumping habit is spreading through France and England and the eastern part of the United States. ["Illustrated World," Sept., 1921]
The fad periodically returned in U.S., but with fading intensity. As a leaping style of punk dance, attested from 1977. The newspaper comic strip by Walt Kelly debuted in 1948 and ran daily through 1975.
pogo stick (n.): 1921; see pogo.