Word Origin & History
O.E. swimman "to move in or on the water, float" (class III strong verb; past tense swamm, pp. swummen), from P.Gmc. *swemjanan (cf. O.S., O.H.G. swimman, O.N. svimma, Du. zwemmen, Ger. schwimmen), from PIE base *swem- "to be in motion," sometimes said to be restricted to Gmc., but possible cognates
are Welsh chwyf "motion," O.Ir. do-sennaim "I hunt," Lith. sundyti "to chase." For the usual IE word, see natatorium
. Sense of "reel or move unsteadily" first recorded 1678; of the head or brain, from 1702. Swimsuit first recorded 1934; swimming hole is from 1867; swimming pool is from 1899. Fig. phrase sink or swim is attested from c.1440, often with ref. to ordeals of suspected witches.
1547, "the clear part of any liquid" (above the sediment), from swim
(v.). Meaning "part of a river or stream frequented by fish" (and hence fishermen) is from 1828, and is probably the source of the fig. meaning "the current of the latest affairs or events" (1869).