con·sti·tu·tive [kónst? t?tiv] adjective 1. forming part: forming a part of something 2. essential: essential to the particular nature or character of something 3. biochemistry formed continuously: describes enzymes that are formed continuously without an external stimulus 4. politics having power to establish institution: having the power to create or establish a system of government, legislative body, or other institution, or to appoint members of official bodies -con·sti·tu·tive·ly, adverb