Source : Webster's Revised Unabridged Dictionary (1913)

Damn \Damn\ (d[a^]m), v. t. [imp. & p. p. {Damned} (d[a^]md or
   d[a^]m"n[e^]d); p. pr. & vb. n. {Damning} (d[a^]m"[i^]ng or
   d[a^]m"n[i^]ng).] [OE. damnen dampnen (with excrescent p),
   OF. damner, dampner, F. damner, fr. L. damnare, damnatum, to
   condemn, fr. damnum damage, a fine, penalty. Cf. {Condemn},
   {Damage}.]
   1. To condemn; to declare guilty; to doom; to adjudge to
      punishment; to sentence; to censure.

            He shall not live; look, with a spot I damn him.
                                                  --Shak.

   2. (Theol.) To doom to punishment in the future world; to
      consign to perdition; to curse.

   3. To condemn as bad or displeasing, by open expression, as
      by denuciation, hissing, hooting, etc.

            You are not so arrant a critic as to damn them [the
            works of modern poets] . . . without hearing.
                                                  --Pope.

            Damn with faint praise, assent with civil leer, And
            without sneering teach the rest to sneer. --Pope.

   Note: Damn is sometimes used interjectionally, imperatively,
         and intensively.

Damn \Damn\, v. i.
   To invoke damnation; to curse. ``While I inwardly damn.''
   --Goldsmith.

Source : WordNet®

damn
     adj 1: used as expletives; "oh, damn (or goddamn)!" [syn: {goddamn}]
     2: expletives used informally as intensifiers; "he's a blasted
        idiot"; "it's a blamed shame"; "a blame cold winter"; "not
        a blessed dime"; "I'll be damned (or blessed or darned or
        goddamned) if I'll do any such thing"; "he's a damn (or
        goddam or goddamned) fool"; "a deuced idiot"; "tired or
        his everlasting whimpering"; "an infernal nuisance" [syn:
        {blasted}, {blame}, {blamed}, {blessed}, {damned}, {darned},
         {deuced}, {everlasting}, {goddam}, {goddamn}, {goddamned},
         {infernal}]

damn
     n : something of little value; "his promise is not worth a
         damn"; "not worth one red cent"; "not worth shucks" [syn:
          {darn}, {hoot}, {red cent}, {shit}, {shucks}, {tinker's
         damn}, {tinker's dam}]
     adv : extremely; "you are bloody right"; "Why are you so all-fired
           aggressive?" [syn: {bloody}, {all-fired}]
     v : wish harm upon; invoke evil upon; "The bad witch cursed the
         child" [syn: {curse}, {beshrew}, {bedamn}, {anathemize},
         {anathemise}, {imprecate}, {maledict}] [ant: {bless}]