"a collection of tools, utensils, etc. adapted as a means to some end," 1620s, from Latin apparatus "tools, implements, equipment; preparation, a preparing," noun of state from past participle stem of apparare "prepare," from ad "to" (see ad-) + parare "make ready" (from PIE root *pere- (1) "to produce, procure").
the breathing apparatus
appalling
Appaloosa
appanage
apparat
apparatchik
apparatus
apparel
apparent
apparently
apparition
appeach