1. (n.) Plural of Apparatus.

2. (n.) Things provided as means to some end.

3. (n.) Hence: A full collection or set of implements, or utensils, for a given duty, experimental or operative; any complex instrument or appliance, mechanical or chemical, for a specific action or operation; machinery; mechanism.

4. (n.) A collection of organs all of which unite in a common function; as, the respiratory apparatus.