Source : Webster's Revised Unabridged Dictionary (1913)

Bang \Bang\, v. i.
   To make a loud noise, as if with a blow or succession of
   blows; as, the window blind banged and waked me; he was
   banging on the piano.

Bang \Bang\, n.
   1. A blow as with a club; a heavy blow.

            Many a stiff thwack, many a bang.     --Hudibras.

   2. The sound produced by a sudden concussion.

Bang \Bang\, v. t.
   To cut squarely across, as the tail of a hors, or the
   forelock of human beings; to cut (the hair).

         His hair banged even with his eyebrows.  --The Century
                                                  Mag.

Bang \Bang\, n.
   The short, front hair combed down over the forehead, esp.
   when cut squarely across; a false front of hair similarly
   worn.

         His hair cut in front like a young lady's bang. --W. D.
                                                  Howells.

Bang \Bang\, Bangue \Bangue\, n.
   See {Bhang}.

Bang \Bang\, v. t. [imp. & p. p. {Banged}; p. pr. & vb. n.
   {Banging}.] [Icel. banga to hammer; akin to Dan. banke to
   beat, Sw. b[*a]ngas to be impetuous, G. bengel club, clapper
   of a bell.]
   1. To beat, as with a club or cudgel; to treat with violence;
      to handle roughly.

            The desperate tempest hath so banged the Turks.
                                                  --Shak.

   2. To beat or thump, or to cause ( something) to hit or
      strike against another object, in such a way as to make a
      loud noise; as, to bang a drum or a piano; to bang a door
      (against the doorpost or casing) in shutting it.

Source : WordNet®

bang
     n 1: a vigorous blow; "the sudden knock floored him"; "he took a
          bash right in his face"; "he got a bang on the head"
          [syn: {knock}, {bash}, {smash}, {belt}]
     2: a sudden very loud noise [syn: {clap}, {eruption}, {blast},
        {loud noise}]
     3: a fringe of banged hair (cut short squarely across the
        forehead)
     4: the swift release of a store of affective force; "they got a
        great bang out of it"; "what a boot!"; "he got a quick
        rush from injecting heroin"; "he does it for kicks" [syn:
        {boot}, {charge}, {rush}, {flush}, {thrill}, {kick}]
     5: a conspicuous success; "that song was his first hit and
        marked the beginning of his career"; "that new Broadway
        show is a real smasher"; "the party went with a bang"
        [syn: {hit}, {smash}, {smasher}, {strike}]

bang
     adv : directly; "he ran bang into the pole"; "ran slap into her"
           [syn: {slap}, {slapdash}, {smack}, {bolt}]

bang
     v 1: strike violently; "slam the ball" [syn: {slam}]
     2: to produce a sharp often metallic explosive or percussive
        sound; "One of them banged the sash of the window nearest
        my bed"
     3: close violently; "He slammed the door shut" [syn: {slam}]
     4: move noisily; "The window banged shut"; "The old man banged
        around the house"
     5: have sexual intercourse with; "This student sleeps with
        everyone in her dorm"; "Adam knew Eve"; "Were you ever
        intimate with this man?" [syn: {roll in the hay}, {love},
        {make out}, {make love}, {sleep with}, {get laid}, {have
        sex}, {know}, {do it}, {be intimate}, {have intercourse},
        {have it away}, {have it off}, {screw}, {fuck}, {jazz}, {eff},
         {hump}, {lie with}, {bed}, {have a go at it}, {get it on},
         {bonk}]
     6: leap, jerk, bang; "Bullets spanged into the trees" [syn: {spang}]

Source : Free On-Line Dictionary of Computing

bang
     
        1. A common spoken name for "!" (ASCII 33), especially when
        used in pronouncing a {bang path} in spoken hackish.  In
        {elder days} this was considered a {CMU}ish usage, with {MIT}
        and {Stanford} hackers preferring {excl} or {shriek}; but the
        spread of {Unix} has carried "bang" with it (especially via
        the term {bang path}) and it is now certainly the most common
        spoken name for "!".  Note that it is used exclusively for
        non-emphatic written "!"; one would not say "Congratulations
        bang" (except possibly for humorous purposes), but if one
        wanted to specify the exact characters "foo!" one would speak
        "Eff oh oh bang".
     
        See {pling}, {shriek}, {ASCII}.
     
        2. An exclamation signifying roughly "I have achieved
        enlightenment!", or "The dynamite has cleared out my brain!"
        Often used to acknowledge that one has perpetrated a {thinko}
        immediately after one has been called on it.
     
        [{Jargon File}]
     
        (1995-01-31)