1942, American English colloquial shortening of politician.
"small body of standing water," Old English pol "small body of water; deep, still place in a stream," from Proto-West Germanic *pōl- (source also of Old Frisian and Middle Low German pol, Dutch poel, Old High German pfuol, German Pfuhl "pool, puddle"), which is of uncertain origin, perhaps a substratum word [Boutkan]. As a short form of swimming pool it is recorded from 1901. Pool party "party at a swimming pool" is by 1965.
"small, dark-brown, northern European predatory quadruped of the weasel family," noted as a chicken-thief and for its strong, offensive smell, early 14c., pol-cat, from cat (n.); the first element is perhaps Anglo-French pol, from Old French poule "fowl, hen" (see pullet (n.)); so called because it preys on poultry [Skeat]. The other alternative is that the first element is from Old French pulent "stinking." Originally the European Putorius foetidus; the name was extended to related North American skunks by 1680s.
English city on the River Mersey, c.1190, Liuerpul "Pool with Muddy Water," from Old English lifer "thick, clotted water" + pol (see pool (n.1)). "The original reference was to a pool or tidal creek now filled up into which two streams drained" [Victor Watts, "Cambridge Dictionary of English Place-Names," 2004]. The adjective and noun Liverpudlian (with jocular substitution of puddle for pool) is attested from 1833.
masc. proper name, the Biblical name of the apostle to the Gentiles, from Latin Paulum (nominative Paulus), a Roman surname of the Aemilian gens, literally "small," from PIE *pau-ro-lo-, suffixed form of root *pau- (1) "few, little." Other forms include Old French Pol, Italian Paolo, Spanish Pablo, Russian Pavel. Paul Pry as a name for a very inquisitive person is by 1820. Related: Paulian; Paulite.
c. 1300 (late 12c. as a surname), polle, "hair of the head; piece of fur from the head of an animal," also (early 14c.) "head of a person or animal," from or related to Middle Low German or Middle Dutch pol "head, top." The sense was extended by mid-14c. to "person, individual" (by polls "one by one," of sheep, etc., is recorded from mid-14c.)
Meaning "collection or counting of votes" is recorded by 1620s, from the notion of "counting heads;" the sense of "the voting at an election" is by 1832. The meaning "survey of public opinion" is recorded by 1902. A poll tax, literally "head tax," is from 1690s. Literal use in English tends toward the part of the head where the hair grows.