bang

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A fringe of hair cut short and straight across the forehead.
• transitive verb To cut (hair) to form bangs.
• noun A sudden loud noise, as of an explosion.
• noun A sudden loud blow or bump.
• noun Informal A sudden burst of action.
• noun Slang A sense of excitement; a thrill.
• intransitive verb To strike heavily and often repeatedly; bump.
• intransitive verb To close suddenly and loudly; slam.
• intransitive verb To handle noisily or violently.
• intransitive verb Vulgar Slang To have sexual intercourse with.
• intransitive verb To make a sudden loud, explosive noise.
• intransitive verb To crash noisily against or into something.
• adverb Exactly; precisely.
• adverb Suddenly; abruptly.
• interjection Used to indicate the sound of an explosion or collision.
• idiom (bang for the/one's) Value returned for investment or effort.

from The Century Dictionary.

• To beat, as with a club or cudgel; thump; cudgel.
• To beat or handle roughly in any way; treat with violence; knock about; drub; defeat: often with about: as, to bang the furniture about.
• To produce a loud noise from or by, as in slamming a door, and the like: as, he went out and banged the door behind him.
• To beat in any quality or action; surpass; excel.
• To strike violently or noisily; thump: usually with against.
• To resound with clashing noises.
• To spring or move with sudden energy or impetus; bounce: as, he banged up at once.
• To cut across: used of hair. To cut (the hair) so as to form a fringe over the forehead: a common fashion with girls and young women.
• To dock (a horse's tail).
• noun The Cuban sardine, Sardinella pseudohispanica.
• With a sudden or violent blow or clap; all of a sudden; abruptly: especially with come or go: as, bang went the guns.
• noun The front hair cut so as to hang evenly over the forehead: often in the plural: as, to wear bangs.
• noun See bhang.
• noun A heavy, resounding blow; a thump, as with a club.
• noun A loud, sudden, explosive noise, as the discharge of a gun or cannon, the slamming of a door, etc.
• noun A sudden, impetuous movement; an energetic dash or bounce: as, he got up with a bang.
• noun A stick; a club.
• noun Synonyms See thump.

from the GNU version of the Collaborative International Dictionary of English.

• noun See bhang.
• intransitive verb To make a loud noise, as if with a blow or succession of blows.
• intransitive verb vulgar slang To have sexual intercourse; to fuck. Considered vulgar and obscene.
• transitive verb To beat, as with a club or cudgel; to treat with violence; to handle roughly.
• transitive verb 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.
• transitive verb vulgar slang To have sexual intercourse with; to fuck; -- usually used with the male as a subject. Considered vulgar or obscene.
• noun A blow as with a club; a heavy blow.
• noun The loud sound produced by a sudden concussion or explosion.
• noun informal A surge of pleasure; a thrill; -- usually used in the phrase get a bang out of.
• noun (Printing & Computers), slang An exclamation point; -- used in verbal descriptions of text, in printing and in computer technology.
• noun vulgar slang An instance of sexual intercourse; a fuck. Considered vulgar and obscene.
• transitive verb To cut squarely across, as the tail of a horse, or the forelock of human beings; to cut (the hair).