A group of citizens represented by an elected official and living in his or her specific district or state. Today, a congressman/woman has an average of 650,000 constituents. A Senator represents an entire state, and the number of constituents varies widely by state. A California Senator, for example, has over 35 million constituents, while a Senator from Wyoming has only about 499,000.
Constituents or one's constituency refers to the people a decision- maker represents. The constituents of a governmental leader are the citizens he or she represents in Parliament or other legislative body. The constituents of a negotiator are the people he or she is negotiating for -- members of a union, perhaps, or of an interest group or business.
All parts necessary to the formation of the whole; composing or being an essential part of the whole; an elementary component of the whole; as in oxygen and hydrogen are the constituent parts of water.