Online Etymology Dictionary

Pannonia: ancient name of the region roughly corresponding to modern Hungary.
panocha (n.): also panoche, 1847, from American Spanish panocha "brown sugar," perhaps ultimately from Latin panucula "tuft," diminutive of panus "tuft, swelling; ear of millet" (see panic (n.2)).
panoply (n.): 1570s, from Greek panoplia "complete suit of armor," from pan- "all" (see pan-) + hopla (plural), "arms" of a hoplites ("heavily armed soldier"); see hoplite. Originally in English figurative, of "spiritual armor," etc. (a reference to Eph. vi); non-armorial sense of "any splendid array" first recorded 1829.
panoptic (adj.): 1826, from Greek panoptos "fully visible, seen by all," from panopes "all-seeing," from pan "all" (see pan-) + optos (see optic). Related: Panoptical.
panopticon (n.): 1768, a type of optical instrument or telescope, from Greek pan "all" (see pan-) + optikon, neuter of optikos "of or for sight" (see optic). Later the name of a type of prison designed by Bentham (1791) in which wardens had a constant view of all inmates, and "a showroom" (1850).
panorama (n.): 1796, "a painting on a revolving cylindrical surface," coined c.1789 by inventor, Irish artist Robert Barker, literally "a complete view," from pan- "all" + Greek horama "sight, spectacle, that which is seen," from horan "to look, see" (see warrant (n.)). Meaning "comprehensive survey" is 1801.
panoramic (adj.): 1813; see panorama + -ic. Panoramic camera is attested from 1878.
pansexual (adj.): 1926 (pansexualism is from 1917), from pan- + sexual. Originally in reference to the view that the sex instinct plays the primary part in all human activity, mental and physical; this was held by his critics to be the view of Freud, therefore a term of reproach leveled at early psychology.
Panslavism (n.): 1846, from German Pansclavismus, coined as a linguistic term by Herkel in 1826.
pansy (n.): mid-15c., from Middle French pensée "a pansy," literally "thought, remembrance," from fem. past participle of penser "to think," from Latin pensare "consider," frequentative of pendere "to weigh" (see pensive). So called because it was regarded as a symbol of thought or remembrance. Meaning "effeminate homosexual man" is first recorded 1929.
pant (v.): mid-15c., perhaps a shortening of Old French pantaisier "gasp, puff, pant, be out of breath, be in distress" (12c.), probably from Vulgar Latin *pantasiare "be oppressed with a nightmare, struggle for breathing during a nightmare," literally "to have visions," from Greek phantasioun "have or form images, subject to hallucinations," from phantasia "appearance, image, fantasy" (see phantasm). Related: Panted; panting.
pant (n.): "a gasping breath," c.1500, from pant (v.).
Pantaloon (n.): skinny, foolish old man in Italian comedy, 1580s; see pantaloons. As a kind of leggings, 1660s.
pantaloons (n.): 1660s, "kind of tights" (originally a French fashion and execrated as such by late 17c. English writers), associated with Pantaloun (1580s), silly old man character in Italian comedy who wore tight trousers over his skinny legs, from Italian Pantalone, originally San Pantaleone, Christian martyr, a popular saint in Venice (Pantaleone in the comedies represents the Venetian). The name is of Greek origin and means "all-compassionate" (or, according to Klein, "entirely lion"). Applied to tight long trousers (replacing knee-breeches) by 1798; pants is a shortened form first recorded 1840.
Panthalassa: "universal sea," such as that which surrounded Pangaea, 1893 (Suess), from pan- "all" (see pan-) + Greek thalassa "sea," a word from a lost pre-Greek Mediterranean language.
pantheism (n.): "belief that God and the universe are identical," from pantheist (n.), which was coined (1705) by Irish deist John Toland (1670-1722), from Greek pan- "all" (see pan-) + theos "god" (see Thea).

Toland's word was borrowed into French, which from it formed panthéisme (1712) which returned to English as pantheism "the doctrine that all is god" in 1732 (no evidence that Toland used pantheism).

Greek pantheios meant "common to all gods" (see pantheon). Other words used at various times for similar notions include panentheism, "philosophy founded on the notion that all things are in God" (1874), from German (1828), coined by Karl Christian Friedrich Krause (1781-1832).
pantheist (n.): 1705, see pantheism + -ist.
pantheistic (adj.): 1732, from pantheist + -ic.
pantheon (n.): c.1300, from Pantheon, name of a temple for all the gods built in Rome c.25 B.C.E. by Agrippa (since 609 C.E. made into the Christian church of Santa Maria Rotonda), from Greek Pantheion (hieron) "(shrine) of all the gods," from pantheion, neuter of pantheios, from pan- "all" (see pan-) + theios "of or for the gods," from theos "god" (see Thea). Sense of any group of exalted persons is first found 1590s.
panther (n.): early 13c., from Old French pantere "panther" (12c.), from Latin panthera, from Greek panther "panther, leopard," probably of Oriental origin. Folk etymology derivation from Greek pan- "all" + ther "beast" led to many curious fables.
panties (n.): 1845, "drawers for men" (derogatory), diminutive of pants; meaning "underpants for women or children" first recorded 1908. Panty raid first attested 1952.
pantisocracy (n.): "ideal Utopian community in which all have equal rights," 1794, literally "equal rule of all," from Greek pant-, comb. form of pantos, genitive of pan "all" (see pan-) + isocratia "equality of power" (see isocracy).
pantomime (n.): 1610s, "mime actor," from Latin pantomimus "mime, dancer," from Greek pantomimos "actor," literally "imitator of all," from panto- (genitive of pan) "all" (see pan-) + mimos "imitator" (see mime (n.)).

Meaning "drama or play without words" first recorded 1735. The English dramatic performances so called, usually at Christmas and with words and songs and stock characters, are attested by this name from 1739; said to have originated c.1717. Related: Pantomimic; pantomimical.
pantomime (v.): 1768, from pantomime (n.). Related: Pantomimed; pantomiming.
pantothenic (adj.): denoting a B-complex vitamin acid, 1933, from Greek pantothen "from all quarters, on every side," from panto-, comb. form of pantos, genitive of pan "all" (see pan-) + -ic. So called because it was found in so many sources.
pantry (n.): early 14c., from Anglo-French panetrie (Old French paneterie) "bread room," from Medieval Latin panataria "office or room of a servant who has charge of food" (literally "bread"), from Latin panis "bread" (see food). Sense in English has evolved so far that its roots in "bread" are no longer felt.
pants (n.): trousers, 1840, see pantaloons. Colloquial singular pant is attested from 1893. To wear the pants "be the dominant member of a household" is first attested 1931. To do something by the seat of (one's) pants "by human instinct" is from 1942, originally of pilots, perhaps with some notion of being able to sense the condition and situation of the plane by engine vibrations, etc. To be caught with (one's) pants down "discovered in an embarrassing condition" is from 1932.
pantsuit (n.): 1966, contraction of pants suit (1964), from pants + suit (n.).
pantyhose (n.): 1963; see panties + hose (n.).
pantywaist (n.): "weak or effeminate male," 1936, from a type of child's garment with short pants that buttoned to the waist of a shirt; see panties + waist.
panzer (adj.): 1940, from of German Panzerdivision "armored unit," from Panzer "tank," literally "armor," from Middle High German panzier, from Old French panciere "armor for the belly," from pance "belly, stomach," from Latin pantex (genitive panticis) "belly" (see paunch).
pap (n.1): "soft food for infants," late 14c., from Old French pape "watered gruel," from Latin pappa, a widespread word in children's language for "food" (e.g. Middle High German and Dutch pap, German Pappe, Spanish, Portuguese papa, Italian pappa), imitative of an infant's noise when hungry; possibly associated with pap (n.2). Meaning "over-simplified idea" first recorded 1540s.
pap (n.2): "nipple of a woman's breast," c.1200, first attested in Northern and Midlands writing, probably from a Scandinavian source (not recorded in Old Norse, but cf. dialectal Swedish pappe), from PIE imitative root *pap- "to swell" (cf. Latin papilla "nipple," papula "a swelling, pimple;" Lithuanian papas "nipple").
pap (n.3): "older man," 1844, shortening of papa.
Pap test (n.): 1963, short for Papanicolaou (1947) in reference to George Nicholas Papanicolaou (1883-1962), Greek-born U.S. anatomist who developed the technique of examining secreted cells to test for cancer.
papa (n.): "father," 1680s, from French papa, from Latin papa, originally a child's word, cf. Greek pappa (vocative) "o father," pappas "father," pappos "grandfather." The native word is daddy; first use of papa was in courtly speech, as a continental affectation, not used by common folk until late 18c.
papacy (n.): late 14c., from Medieval Latin papatia "papal office," from Late Latin papa "pope" (see pope). Old English had papdom in this sense.
papal (adj.): late 14c., from Old French papal (late 14c.) and directly from Medieval Latin papalis "pertaining to the pope," from papa (see pope).
paparazzi (n.): 1961, from Italian Paparazzo (plural paparazzi) surname of the freelance photographer in Federico Fellini's 1959 film "La Dolce Vita." The surname itself is of no special significance; it is said to be a common one in Calabria, and Fellini is said to have borrowed it from a travel book, "By the Ionian Sea," in which occurs the name of hotel owner Coriolano Paparazzo.
paparazzo (n.): see paparazzi.
papaw (n.): 1620s, variant of papaya (q.v.), used from 1760 to designate the papaw tree.
papaya (n.): 1590s for fruit, 1610s for tree, from Spanish, probably from Arawakan (West Indies) papaya.
paper (n.): mid-14c., from Anglo-French paper, Old French papier "paper, document," from Latin papyrus "paper, paper made of papyrus stalks" (see papyrus).

Meaning "paper money" attested from 1722. As shortened form of newspaper, first attested 1640s. In plural, "collection of papers to establish one's identity, credentials, etc.," it is attested from 1680s. Paper chase is British slang from 1932.
paper (v.): 1590s, "to write down on paper," from paper (n.). Meaning "to decorate a room with paper hangings" is from 1774. Related: Papered; papering. Verbal phrase paper over in the figurative sense is from 1955, from the notion of hiding plaster cracks with wallaper.
paper (adj.): 1590s, from paper (n.). Figurative of something flimsy or unsubstantial from 1716. Paper tiger (1952) translates Chinese tsuh lao fu, popularized by Mao Zedong. Paper doll attested from 1849; paper plate from 1723.
paper-weight (n.): "heavy object used to hold down papers," 1858, from paper (n.) + weight (n.).
paperback (n.): 1899, from paper (n.) + back (n.). Adjective paper-backed attested from 1888.
paperless (adj.): 1938 of cigarettes; 1967 of banks; 1971 of offices, from paper (n.) + -less.
paperwork (n.): 1580s, "things made of paper," from paper (n.) + work (n.). Meaning "work done on paper" is from 1889.
papier-mache (n.): also papier mache, 1753, from French papier-mâché, literally "chewed paper," from Old French papier "paper" (see paper (n.)) + mâché "compressed, mashed," from past participle of mâcher, literally "to chew," from Late Latin masticare "masticate" (see mastication).