资料来源 : pyDict

额外的,外加的额外的事物,额外收费之物特别地,非常地;除外

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Extra \Ex"tra\, n.
   1. 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.

   2. An edition of a newspaper issued at a time other than the
      regular one.

   3. (Cricket) A run, as from a bye, credited to the general
      score but not made from a hit.

   4. Something of an extra quality or grade.

Extra \Ex"tra\, n.; pl. {Extras}.
   Something in addition to what is due, expected, or customary;
   something in addition to the regular charge or compensation,
   or for which an additional charge is made; as, at European
   hotels lights are extras. [Colloq.]

Extra \Ex"tra\, a.
   Beyond what is due, usual, expected, or necessary;
   additional; supernumerary; also, extraordinarily good;
   superior; as, extra work; extra pay. ``By working extra
   hours.'' --H. Spencer.

资料来源 : WordNet®

extra
     adj 1: further or added; "called for additional troops"; "need
            extra help"; "an extra pair of shoes"; "I have no
            other shoes"; "there are other possibilities" [syn: {other(a)},
             {additional}]
     2: more than is needed, desired, or required; "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" [syn: {excess}, {redundant},
         {spare}, {supererogatory}, {superfluous}, {supernumerary},
         {surplus}]
     3: added to a regular schedule; "a special holiday flight";
        "put on special buses for the big game" [syn: {special}]

extra
     n 1: a minor actor in crowd scenes [syn: {supernumerary}, {spear
          carrier}]
     2: an additional edition of a newspaper (usually to report a
        crisis)
     3: something additional of the same kind; "he always carried
        extras in case of an emergency" [syn: {duplicate}]

extra
     adv : unusually or exceptionally; "an extra fast car"

资料来源 : Free On-Line Dictionary of Computing

EXTRA
     
        Object-oriented, Pascal style, handles sets.  "A Data Model
        and Query Language for EXODUS", M.J. Carey et al, SIGMOD 88
        Conf Proc, pp.413- 423, ACM SIGMOD Record 17:3 (Sept 1988).