Constituent, n.
1. The person or thing which constitutes, determines, or constructs. Their first composure and origination require a higher and nobler constituent than chance. Sir M. Hale
2. That which constitutes or composes, as a part, or an essential part; a component; an element. We know how to bring these constituents together, and to cause them to form water. Tyndall.
3. One for whom another acts; especially, one who is represented by another in a legislative assembly; -- correlative to representative. The electors in the district of a representative in Congress, or in the legislature of a State, are termed his constituents. Abbot. To appeal from the representatives to the constituents. Macaulay.
4. (Law)
1 more senses
A person who appoints another to act for him as attorney in fact. Burrill.
1 other Webster entry under this spelling
Constituent, a.
1. Serving to form, compose, or make up; elemental; component. Body, soul, and reason are the three parts necessarily constituent of a man. Dryden.
2. Having the power of electing or appointing. A question of right arises between the constituent and representative body. Junius.
Shades of meaning
Fernald has no entry of its own for constituent; he lists it under part.
Where he writes about it:
A component, constituent, ingredient, or element is a part of some compound or mixture; an element is necessary to the existence, as a component or constituent is necessary to the completeness of that which it helps to compose; an ingredient may be foreign or accidental. — from part