An equipment of things provided and adapted as means to some end; especially, a collection, combination, or set of machinery, tools, instruments, utensils, appliances, or materials intended, adapted, and necessary for the accomplishment of some purpose, such as mechanical work, experimenting, etc.: as, chemical, philosophical, or surgical apparatus.Specifically— In physiology, a collection of organs which, though differing in structure, all minister to the same function: as, the respiratory apparatus; the digestive apparatus.A collection of materials for any literary work: as, critical apparatus for the study of the Greek text of the New Testament.