What is the meaning of extra?

noun

• A minor actor in crowd scenes.
  • synonyms: supernumerary, spear carrier
• An additional edition of a newspaper (usually to report a crisis. )
• Something additional of the same kind.
  • usage: "he always carried extras in case of an emergency"
  • synonyms: duplicate

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, redundant, spare, supererogatory, superfluous, supernumerary, surplus
• Added to a regular schedule.
  • usage: "a special holiday flight"; "put on special buses for the big game"
  • synonyms: special
• Further or added.
  • usage: "called for additional troops"; "need extra help"; "an extra pair of shoes"
  • synonyms: additional

adverb

• Unusually or exceptionally.
  • usage: "an extra fast car"