古英語の lepen（跳ぶ）から。語源的には elope（駆け落ち）、 gallop（駆け足）と同じ。おそらく PIE *klei（曲げる、回す、傾ける）からさらに派生したもので、語源的には lean（傾く）、 incline（傾斜）と同じ。
英語の語源
leap
leap: [OE] Prehistoric Germanic *khlaupan was the source of English leap, and of its relatives German laufen and Dutch loopen (these both denote ‘run’, a meaning which leap used to have – and which is preserved in its first cousins lope [15], a borrowing from Old Norse, and elope). It is not known where it ultimately came from, although a connection has been suggested with Indo-European *kloub-, source of Lithuanian ?lubuoti ‘limp’. The verb loaf may be related. => loaf, lope
leap (v.)
c. 1200, from Old English hleapan "to jump, run, leap" (class VII strong verb; past tense hleop, past participle hleapen), from Proto-Germanic *hlaupan (cognates: 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.
leap (n.)
c. 1200, from Old English hliep, hlyp (West Saxon), *hlep (Mercian, Northumbrian) "a leap, bound, spring, sudden movement; thing to leap from;" common Germanic (cognates: 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.
例文
1. Warwicks leap to third in the table，31 points behind leaders Essex.
ウォリックチームは順位の中で3位に浮上し、リードしていたエセックスチームに31点遅れた。
2.The scale of migration took a quantum leap in the early 1970 s.
1970年代初頭、移民の規模は急激に拡大した。
3.The result has been a giant leap in productivity.
その結果、生産性が大幅に向上した。
4.Prudent people are not going to take a leap in the dark.
慎重な人は簡単に冒険しません。
5.Once more he 's Making a leap into the unknown without a plan.