What is the meaning of supernumerary?

noun

• A person serving no apparent function.
  • usage: "reducing staff is difficult because our employees include no supernumeraries"
• A minor actor in crowd scenes.
  • synonyms: spear carrier, extra

adjective

• More than is needed, desired, or required.
  • usage: "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"
  • synonyms: excess, extra, redundant, spare, supererogatory, superfluous, surplus