noun, plural ap·pa·rat·us, ap·pa·rat·us·es.
- a group or combination of instruments, machinery, tools, materials, etc., having a particular function or intended for a specific use: Our town has excellent fire-fighting apparatus.
- any complex instrument or mechanism for a particular purpose.
- any system or systematic organization of activities, functions, processes, etc., directed toward a specific goal: the apparatus of government; espionage apparatus.
- Physiology. a group of structurally different organs working together in the performance of a particular function: the digestive apparatus.
noun plural -ratus or -ratuses
- a collection of instruments, machines, tools, parts, or other equipment used for a particular purpose
- a machine having a specific functionbreathing apparatus
- the means by which something operates; organizationthe apparatus of government
- anatomy any group of organs having a specific function
1620s, from Latin apparatus “tools, implements, equipment; preparation, a preparing,” noun of state from past participle stem of apparare “prepare,” from ad- “to” (see ) + parare “make ready” (see ).
n. pl. apparatus
- An integrated group of materials or devices used for a particular purpose.
- A group or system of organs that collectively performs a specific function or process.