O.E. hleapan "to jump, run, leap" (class VII strong verb; past tense hleop, pp. hleapen), from P.Gmc. *khlaupan (cf. O.S. hlopan, O.N. hlaupa, O.Fris. hlapa, Du. lopen, Ger. laufen "to run," Goth. us-hlaupan "to jump up"), of uncertain origin, with no known cognates beyond Germanic. The noun is O.E. hlyp (Anglian *hlep). Leap-frog, the children's game, is attested from 1590s.