"a savoury dish of Italian origin, consisting of a base of dough, spread with a selection of such ingredients as olives, tomatoes, cheese, anchovies, etc., and baked in a very hot oven" [OED, 1989], 1845, from Italian pizza, originally "cake, tart, pie," a name of uncertain origin.

The 1907 "Vocabolario Etimologico della Lingua Italiana" reports it is said to be from dialectal pinza "clamp" (from Latin pinsere "to pound, stamp") which might refer to the folded style of pizza that is made in some regions of Italy (see quote below.)

The pizza is a sort of bun [original: un talmouse comme on en fait à St-Denis, lit. "a talmouse like one gets in St-Denis."]; it is round, and made of the same dough as bread. It is of different sizes according to the price. […] At first sight the pizza appears to be a simple dish, upon examination it proves to be compound. The pizza is prepared with bacon, with lard, with cheese, with tomatas, with fish. ["Sketches of Naples" by Alexandre Dumas, translated by A. Roland for Arthur's Magazine, Aug. 1845.]

A pizza is manufactured, as far as I can ascertain, by garnishing a slab of reinforced asphalt paving with mucilage, whale-blubber and the skeletons of small fishes, baking same to the consistency of a rubber heel, and serving piping-hot with a dressing of molten lava. ["Simon Stylites," in The Bergen Evening Record, May 15, 1931]

"a shop where pizzas are made, sold, or eaten," by 1928 in restaurant names around New York city, from pizza with ending as in cafeteria. In 1920s and '30s it sometimes also meant "pizza pie" itself.

U.S. student slang shortening of pizza, attested from 1968.

Proto-Indo-European root meaning "to split," with derivatives in Germanic "referring to biting (hence also to eating and to hunting) and woodworking" [Watkins].

It might form all or part of: abet; bait (n.) "food used to attract prey;" bait (v.) "to torment, persecute;" bateau; beetle (n.1) "type of insect; bit (n.1) "small piece;" bite; bitter; bitter end; boat; boatswain; -fid; fissile; fission; fissure; giblets; pita; pizza; vent (n.).

It might also be the source of: Sanskrit bhinadmi "I cleave," Latin Latin findere "to split, cleave, separate, divide," Old High German bizzan "to bite," Old English bita "a piece bitten off, morsel," Old Norse beita "to hunt with dogs," beita "pasture, food."

in the internet sense, c. 2000, short for robot. Modern use has coincidental affinities with earlier uses, such as "parasitical worm or maggot" (1520s), which is of unknown origin; and Australian-New Zealand slang "worthless, troublesome person" (World War I-era). The method of minting new slang by clipping the heads off words does not seem to be old or widespread in English. Examples (za from pizza, zels from pretzels, rents from parents) are American English student or teen slang and seem to date back no further than late 1960s. Also compare borg, droid.

flowering plant in the mint family, used for thousands of years in medicine and cookery, 1771, from Spanish or American Spanish oregano, from Latin origanus, origanum, from Greek oreiganon, from oros "mountain" (see oread) + ganos "brightness, ornament." In Europe, the dried leaves of wild marjoram; in southwestern America, the name is given to a different, and more pungent, shrub, also known as Mexican oregano.

A staple of Italian cooking, its modern American popularity is said to date to World War II; a 1957 food industry publication in the U.S. says of oregano, "Here is a spice that was unheard of in 99 out of 100 households just a few years ago." Its rise seems to coincide with the popularity of pizza. The older form of the word in English was the Latin-derived origanum (c. 1300), also origan (early 15c., from Old French). Late Old English had it as organe.