n. 1. a device capable of launching a rocket.
Syn. -- rocket launcher. [ WordNet 1.5 ]

2. A device which launches aircraft from an aircraft carrier; -- it provides additional velocity to the airplane, to supplement that from the airplane's engines, so that the airplane rapidly achieves a velocity sufficient to sustain it in flight when taking off.
Syn. -- catapult. [ WordNet 1.5 ]