under or below an object or a surface; at a lower place or level; directly beneath; "we could see the original painting underneath"; "a house with a good foundation underneath"
on the lower or downward side; on the underside of; "a chest of drawers all scratched underneath"
(American football) a play in which a defensive player is allowed to cross the line of scrimmage and then blocked off as the runner goes through the place the lineman vacated
a game in which one child bends down and another leaps over
advancing as if in the child's game, by leaping over obstacles or competitors; "the company still believes the chip is a leapfrog in integration and will pay huge dividends"
progress by large jumps instead of small increments