1. noun /kʌmˈpoʊnənt/
A smaller, self-contained part of a larger entity. Often refers to a manufactured object that is part of a larger device.
A CPU is a component of a computer.
2. adjective /kʌmˈpoʊnənt/
a) Making up a larger whole; as a component word.
b) Made up of smaller complete units in combination; as a component stereo.
Wikipedia foundation.