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.