Launch

1. The largest ship's boat carried by a warship – usually an open boat and, in more recent times, fitted with an engine. Historically, both were fitted to be rowed or sailed vessels.
2. In modern usage, a large motorboat; e.g. a harbor master's launch.
3. An elegant power boat of traditional character with a displacement hull; e.g. a slipper launch.
4. To dispatch a newly built ship down a slipway, usually with ceremony, prior to fitting-out and commissioning.
5. To put into the water any boat that is stored or temporarily kept out of the water; e.g. "launch the lifeboat" or "launch a dinghy".