Adjective surplus has 1 sense
  1. excess, extra, redundant, spare, supererogatory, superfluous, supernumerary, surplus - 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"
    Antonym: necessary (indirect, via unnecessary)
,Noun surplus has 1 sense
  1. excess, surplus, surplusage, nimiety - a quantity much larger than is needed
    --1 is a kind of overabundance, overmuch, overmuchness, superabundance