Made of several parts that keep their identity within the whole. A composite is joined rather than merged.
Latin compositus, past participle of componere (to put together); made of several parts joined so each keeps its own identity rather than dissolving into the whole.
Latin componere is to put together, not to dissolve together, and a composite keeps that distinction load-bearing: each part remains countable inside the whole it joined. Take the whole apart and every part comes back out exactly as it went in.