adjective
(not comparable) Beyond what is due, usual, expected, or necessary; extraneous; additional; supernumerary.
(not comparable, dated) Extraordinarily good; superior.
(comparable, slang) Over the top; going beyond what is normal or appropriate, often in a dramatic manner.
adverb
(informal) To an extraordinary degree.
noun
Something additional, such as an item above and beyond the ordinary school curriculum, or added to the usual charge on a bill.
An extra edition of a newspaper, which is printed outside of the normal printing cycle, for example to report an important late-breaking event.
(cricket) A run scored without the ball having hit the striker's bat - a wide, bye, leg bye or no ball.
(acting) A supernumerary or walk-on in a film or play.
(slang) The state or trait of being over the top, of behaving in an overly dramatic manner.
Something of an extra quality or grade.
(Singapore, military, countable) A day of extra duties (often, over the weekends) in camp, as a form of punishment. Used in the phrase “to sign extra”, meaning one has been assigned extras as punishment.