1. act of launching; act of setting afloat; act of sending out; act of starting or initiating; commencement, inauguration; large motorboat; large boat carried by a warship. put a boat in the water; send forth; start; run, activate (computers); inaugurate; throw; break into, burst into. launcharea a platform from which rockets or space craft are launched [syn: launching pad, launchpad, launch pad, pad]