constituent

adjective

1. necessary in forming or making up a whole; component: a constituent part
2. that can or does appoint or vote for a representative
3. authorized to make or revise a political constitution or establish a government: a constituent assembly

noun

1. a person who appoints another to act as agent or representative
2. a member of a constituency, esp. any of the voters represented by a particular official
3. a necessary part or element; component
4. an element of a word or construction (Ex.: in “they painted signs” the main elements they and painted signs are called immediate constituents; the further morphologically indivisible elements they, paint, -ed, sign, and -s are called ultimate constituents)