1. [adjective] Having the power or authority to constitute, establish or enact something
2. [adjective] Having the power or authority to appoint someone to office
3. [adjective] Extremely important, essential
4. [adjective] That forms a constituent part of something else
5. [adjective] (biochemistry) (of an enzyme) that is continuously produced at a constant rate
6. [adjective] Constitutional in the structure of something (especially your physical makeup).
