apparatus >> /ˌæpəˈrædəs/
Definition: [noun] The technical equipment or machinery needed for a particular activity or purpose.
Example: laboratory apparatus
Definition: [noun] A complex structure within an organization or system.
Example: the apparatus of government
Definition: [noun] A collection of notes, variant readings, and other matter accompanying a printed text.
Example: one thing about the book's apparatus does irritate: the absence of an index of titles