enotes something compound, or made up of several others united together. Thus,

Composite Numbers are such as can be measured exactly by a number exceeding unity; as 6 by 2 or 3, or 19 by 5; so that 4 is the lowest composite number. Composite numbers, between themselves, are those which have some common measure besides unity; as 12 and 15, both of which are measured by 3.