Definition of "Extra" :

noun: something additional of the same kind

"He always carried extras in case of an emergency."

noun: an additional edition of a newspaper (usually to report a crisis)

noun: a minor actor in crowd scenes

adjective: further or added

"Need extra help."

adjective: more than is needed, desired, or required

"Found some extra change lying on the dresser."

adjective: added to a regular schedule

adverb: unusually or exceptionally

"An extra fast car."