n.; pl.Apparatus, also rarely Apparatuses [ L., from apparare, apparatum, to prepare; ad + prepare to make ready. ] 1. Things provided as means to some end. [ 1913 Webster ]
2. 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. [ 1913 Webster ]
3. (Physiol.) A collection of organs all of which unite in a common function; as, the respiratory apparatus. [ 1913 Webster ]