leapˈfrog noun

1. A game in which two people, esp children, take turns in vaulting each other, the one stooping or crouching to become the other's vaulting-horse
2. Any similar vault or jump (also figurative)
3. A method of advancing against an enemy force in which one part of an army engages with the enemy whilst the rear part advances (military)

transitive verb and intransitive verb (leapˈfrogging; leapˈfrogged)

1. To jump (over) as in leapfrog (also figurative)
2. To go in advance of each other alternately (military; also figurative)

leapˈing-house noun (Shakespeare)

A brothel

leapˈing-time noun (Shakespeare)

Active youth

leap second noun

A second added to or subtracted from one scale of time whenever necessary, to bring that scale into harmony with another scale or with the rotation of the earth

leap year noun

A year with an intercalary day (perh because any anniversary after that day misses or leaps over a day of the week)

by leaps and bounds

1. By a large amount or extent
2. Very quickly

leap in the dark

An act of which the consequences cannot be foreseen