Performed to an extent not enjoined, or not required, by duty or necessity; as, supererogatory services.
source: Webster 1913
adjective satellite
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 s.
