extra Look up extra at Dictionary.com
1650s as a stand-alone adjective; also used as an adverb and noun in 17c. (see extra-); modern usages -- including sense of "minor performer in a play" (1777) and "special edition of a newspaper" (1793) -- all probably are from shortenings of extraordinary, which was used extensively in 18c. as noun and adverb in places we would use extra today.