extra
noun
a minor actor in crowd scenes
an additional edition of a newspaper (usually to report a crisis)
something additional of the same kind
“he always carried extras in case of an emergency”
Synonymsduplicate
adjective
more than is needed, desired, or required
“trying to lose excess weight”
“found some extra change lying on the dresser”
added to a regular schedule
“a special holiday flight”
“put on special buses for the big game”
Synonymsspecialfurther or added
“called for additional troops”
“need extra help”
Synonymsadditional
adverb
unusually or exceptionally
“an extra fast car”
Source: WordNet 3.1, Princeton University