1. [n]  an impact (as from a collision); "the bump threw him off the bicycle"
2. [n]  something that bulges out or is protuberant or projects from a form
3. [n]  a lump on the body caused by a blow
4. [v]  knock against with force or violence; "My car bumped into the tree"
5. [v]  remove or force from a position of dwelling previously occupied; "The new employee dislodged her by moving into her office space"
6. [v]  dance erotically, as in"bump and grind": dance with the pelvis thrust forward
7. [v]  come upon, as if by accident; meet with; "We find this idea in Plato"; "I happened upon the most wonderful bakery not very far from here"; "She chanced upon an interesting book in the bookstore the other day"
8. [v]  assign to a lower position; reduce in rank; "She was demoted because she always speaks up"

Bump
An automobile collision at an intersection in Beverly Hills brings together the four narrative focuses of this novel: a cop whose wife has just dumped him, a woman with serious doubts about her impending marriage, a wealthy woman who is dissatisfied with her life and gets by on sexual fantasies, and a man who lived in the car that was totaled in the accident.

more details ...

1. \Bump\, v. t. [imp. & p. p. {Bumped}; p. pr. & vb. n.
   {Bumping}.] [Cf. W. pwmp round mass, pwmpiaw to thump, bang,
   and E. bum, v. i., boom to roar.]
   To strike, as with or against anything large or solid; to
   thump; as, to bump the head against a wall.
   

2. \Bump\, v. i.
   To come in violent contact with something; to thump.
   ``Bumping and jumping.'' --Southey.
   

3. \Bump\, n. [From {Bump} to strike, to thump.]
   1. A thump; a heavy blow.
   2. A swelling or prominence, resulting from a bump or blow; a
      protuberance.
            It had upon its brow A bump as big as a young
            cockerel's stone.                     --Shak.
   3. (Phren.) One of the protuberances on the cranium which are
      associated with distinct faculties or affections of the
      mind; as, the bump of ``veneration;'' the bump of
      ``acquisitiveness.'' [Colloq.]
   4. The act of striking the stern of the boat in advance with
      the prow of the boat following. [Eng.]
   

4. \Bump\, v. i. [See {Boom} to roar.]
   To make a loud, heavy, or hollow noise, as the bittern; to
   boom.
         As a bittern bumps within a reed.        --Dryden.
   

5. \Bump\, n.
   The noise made by the bittern.
   

Increment. E.g. C's ++ operator. It is used especially of counter variables, pointers and index dummies in "for", "while", and "do-while" loops.