supernumerary (Adjective) — More than is needed, desired, or required. ex. "supernumerary ornamentation" ex. "extra ribs as well as other supernumerary internal parts"
supernumerary (Noun) — A person serving no apparent function. ex. "reducing staff is difficult because our employees include no supernumeraries"
supernumerary (Noun) — A minor actor in crowd scenes.