extra

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. More than or beyond what is usual, normal, expected, or necessary. See Synonyms at superfluous.
2. adj. Better than ordinary; superior: extra fineness.
3. adj. Subject to an additional charge: Coffee does not come with dinner but is extra.
4. n. Something more than is usual or necessary.
5. n. Something, such as an accessory on a motor vehicle, for which an additional charge is made.
6. n. A special edition of a newspaper.
7. n. An additional or alternate worker.
8. n. A performer hired to play a minor part, as in a crowd scene in a film.
9. n. Something of exceptional quality.
10. adv. To an exceptional extent or degree; unusually: extra dry.

Century Dictionary and Cyclopedia

1. More than what is usual, or than what is due, appointed, or expected; supplementary; additional; supernumerary: as, an extra price; an extra edition of a newspaper; extra diet; extra charges at a boarding-school.
2. n. Something in addition to what is usual or expected; something over and above the usual course or charge, or beyond what is usual.
3. n. Specifically An edition or a copy of a newspaper issued at an unusual hour to convey special intelligence.
4. Beyond the ordinary standard or measure; extraordinarily; unusually; uncommonly: as, this is done extra well; that is an extra high price.
5. A prefix of Latin origin, originally an adverb and preposition, meaning ‘outside, beyond.’ ; In Latin, and in modern formations on Latin analogies, it is especially used— as a preposition in composition with a noun, the preposition with its object noun forming a unitary phrase to which is then attached an adjective termination, as in extraordinary (Latin extraordinarius). pertaining to or characterized by something beyond the usual order (extra ordinem)
6. n. In cricket, a score or run not made from the bat, as a bye or a wide: usually in plural.
7. Used in trade to denote a size somewhat larger than that, mentioned: as, extra elephant folio; extra foolscap octavo.

Wiktionary

1. adj. Beyond what is due, usual, expected, or necessary; extraneous; additional; supernumerary.
2. adj. Extraordinarily good; superior; as extra work, extra pay.
3. adv. informal To an extraordinary degree.
4. n. cricket A run scored without the ball having hit the striker's bat - a wide, bye, leg bye or no ball; in Australia referred to as a sundry
5. n. an extra edition of a newspaper, which is printed outside of the normal printing cycle
6. n. A supernumerary or walk-on in a film or play

GNU Webster's 1913

1. adj. Beyond what is due, usual, expected, or necessary; additional; supernumerary; also, extraordinarily good; superior.
2. n. Something in addition to what is due, expected, or customary; esp., an added charge or fee, or something for which an additional charge is made.
3. n. An edition of a newspaper issued at a time other than the regular one.
4. n. (Cricket) A run, as from a bye, credited to the general score but not made from a hit.
5. n. Something of an extra quality or grade.

WordNet 3.0

1. n. something additional of the same kind
2. adj. more than is needed, desired, or required
3. adj. further or added
4. n. a minor actor in crowd scenes
5. adj. added to a regular schedule
6. adv. unusually or exceptionally
7. n. an additional edition of a newspaper (usually to report a crisis)