Do you know ghouls from goblins and ghosts?
c.1200, from Old English hleapan "to jump, run, leap" (class VII strong verb; past tense hleop, past participle hleapen), from Proto-Germanic *khlaupan (cf. Old Saxon hlopan, Old Norse hlaupa, Old Frisian hlapa, Dutch lopen, Old High German hlouffan, German laufen "to run," Gothic us-hlaupan "to jump up"), of uncertain origin, with no known cognates beyond Germanic. Leap-frog, the children's game, is attested by that name from 1590s; figurative use by 1704.
First loke and aftirward lepe [proverb recorded from mid-15c.]Related: Leaped; leaping.
c.1200, from Old English hliep, hlyp (West Saxon), *hlep (Mercian, Northumbrian) "a leap, bound, spring, sudden movement; thing to leap from;" common Germanic (cf. Old Frisian hlep, Dutch loop, Old High German hlouf, German lauf); from the root of leap (v.). Leaps has been paired with bounds since at least 1720.
Language for the Expression of Associative Procedures.
ALGOL-based formalism for sets and associative retrieval, for TX-2. Became part of SAIL.
"An ALGOL-based Associative Language", J.A. Feldman et al, CACM 12(8):439-449 (Aug 1969).