Origin: Latin suffix -ary
Supernumerary has 5 different meanings across 2 categories:
a person serving no apparent function
"reducing staff is difficult because our employees include no supernumeraries"
a minor actor in crowd scenes
A person who works in a group, association, or public office without forming part of the regular staff (the numerary).
more than is needed, desired, or required
"trying to lose excess weight"
"found some extra change lying on the dresser"
"yet another book on heraldry might be thought redundant"
"skills made redundant by technological advance"
"sleeping in the spare room"
"supernumerary ornamentation"
"it was supererogatory of her to gloat"
"delete superfluous (or unnecessary) words"
"extra ribs as well as other supernumerary internal parts"
"surplus cheese distributed to the needy"
Greater in number than.