To launch a rocket, missile, or satellite means to send it into the air or into space.

To launch a ship or a boat means to put it into water, often for the first time after it has been built.

To launch a large and important activity, for example a military attack, means to start it.

If a company launches a new product, it makes it available to the public.

A launch is a large motorboat that is used for carrying people on rivers and lakes and in harbours.