further or added; "called for additional troops"; "need extra help"; "an extra pair of shoes"
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"
added to a regular schedule; "a special holiday flight"; "put on special buses for the big game"
something additional of the same kind; "he always carried extras in case of an emergency"
an additional edition of a newspaper (usually to report a crisis)
a minor actor in crowd scenes
Phosphorus - a multivalent nonmetallic element of the nitrogen family that occurs commonly in inorganic phosphate rocks and as organic phosphates in all living cells; is highly reactive and occurs in several allotropic forms