Snap back (Football), the act of snapping back the ball.

Snap beetle, or Snap bug (Zo["o]l.), any beetle of the family Elaterid[ae], which, when laid on its back, is able to leap to a considerable height by means of a thoracic spring; -- called also snapping beetle.

Snap flask (Molding), a flask for small work, having its sides separable and held together by latches, so that the flask may be removed from around the sand mold.

Snap judgment, a judgment formed on the instant without deliberation.

Snap lock, a lock shutting with a catch or snap.

Snap riveting, riveting in which the rivets have snapheads formed by a die or swaging tool.

Snap shot, a quick offhand shot, without deliberately taking aim.

Source: Webster's Revised Unabridged Dictionary (1913)