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

accoutrement , appliance , black box * , contraption , device , dingbat , doodad * , doohickey * , furnishings , gaff , gear , gimcrack * , gimmick , gizmo * , grabber , habiliments , idiot box * , implement , jigger , job * , machine , machinery , means , mechanism , outfit , paraphernalia , provisions , setup , stuff , supplies , tackle , thingamajig * , tools , utensils , whatchamacallit , whatsis , whosis , widget * , bureaucracy , chain of command , hierarchy , network , structure , contrivance , accouterment , equipment , material , materiel , rig , thing , turnout , appurtenances , armamentarium , baggage , belongings , doohickey , fixture , gadget , gizmo , goods , instrument , invention , junk , knickknack , machination , notion , project , stratagem , tool , trappings , utensil , utility