Exceeding a number stated or prescribed: as, a supernumerary officer in a regiment.Exceeding a necessary or usual number.n. A person or thing beyond the number stated, or beyond what is necessary or usual; especially, a person not formally a member of a regular body or staff of officials or employees, but retained or employed to act as an assistant or substitute in case of necessity.n. Specifically— A military officer attached to a corps or arm of the service where no vacancy exists. Such an officer receives, in the United States army, the rank of brevet second lieutenant, or additional second lieutenant.n. Theat., one not belonging to the regular company, who appears on the stage, but has no lines to speak. Often colloquially abbreviated super and supe.