The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

            He shall not live; look, with a spot I damn him.
                                                  --Shak.
      [1913 Webster]

   2. (Theol.) To doom to punishment in the future world; to
      consign to perdition; to curse.
      [1913 Webster]

   3. To condemn as bad or displeasing, by open expression, as
      by denuciation, hissing, hooting, etc.
      [1913 Webster]

            You are not so arrant a critic as to damn them [the
            works of modern poets] . . . without hearing.
                                                  --Pope.
      [1913 Webster]

            Damn with faint praise, assent with civil leer,
            And without sneering teach the rest to sneer.
                                                  --Pope.
      [1913 Webster]

   Note: Damn is sometimes used interjectionally, imperatively,
         and intensively.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Damn \Damn\, v. i.
   To invoke damnation; to curse. "While I inwardly damn."
   --Goldsmith.
   [1913 Webster]

WordNet (r) 3.0 (2006):

damn
    adv 1: extremely; "you are bloody right"; "Why are you so all-
           fired aggressive?" [syn: bloody, damn, all-fired]
    adj 1: used as expletives; "oh, damn (or goddamn)!" [syn:
           damn, 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"; "an infernal
       nuisance" [syn: blasted, blame, blamed, blessed,
       damn, damned, darned, deuced, goddam, goddamn,
       goddamned, infernal]
    n 1: something of little value; "his promise is not worth a
         damn"; "not worth one red cent"; "not worth shucks" [syn:
         damn, darn, hoot, red cent, shit, shucks,
         tinker's damn, tinker's dam]
    v 1: wish harm upon; invoke evil upon; "The bad witch cursed the
         child" [syn: curse, beshrew, damn, bedamn,
         anathemize, anathemise, imprecate, maledict] [ant:
         bless]

The Devil's Dictionary (1881-1906):

DAMN, v.  A word formerly much used by the Paphlagonians, the meaning
of which is lost.  By the learned Dr. Dolabelly Gak it is believed to
have been a term of satisfaction, implying the highest possible degree
of mental tranquillity.  Professor Groke, on the contrary, thinks it
expressed an emotion of tumultuous delight, because it so frequently
occurs in combination with the word _jod_ or _god_, meaning "joy."  It
would be with great diffidence that I should advance an opinion
conflicting with that of either of these formidable authorities.