1796: The sudden fall of a river to a lower level.
1486: Supposedly a name for a group of leopards, spelled as lepe.
1747: In mining, a fault or dislocation of the strata
1620: Parched peas, as in leap pease.
1607: The action of a female animal. (Why a male animal doesn't leap in the seventeenth century, I have no idea.)
And my favorite, because it sounds so cool, like you could build a story around it:
1698: A leap in the dark, "a hazardous action taken with uncertain consequences"
And that's just a few of the definitions for the noun (another is a basket for fish; I had no idea). The verb form has even more definitions.
Happy leap day!