bum
     adj : of very poor quality [syn: {cheap}, {cheesy}, {chintzy}, {crummy},
            {punk}, {sleazy}, {tinny}]
     n 1: a person who is deemed to be despicable or contemptible;
          "only a rotter would do that"; "kill the rat"; "throw
          the bum out"; "you cowardly little pukes!"; "the British
          call a contemptible person a `git'" [syn: {rotter}, {dirty
          dog}, {rat}, {skunk}, {stinker}, {stinkpot}, {puke}, {crumb},
           {lowlife}, {scum bag}, {so-and-so}, {git}]
     2: a disreputable vagrant; "a homeless tramp"; "he tried to
        help the really down-and-out bums" [syn: {tramp}, {hobo}]
     3: person who does no work; "a lazy bum" [syn: {idler}, {loafer},
         {do-nothing}, {layabout}]
     4: the fleshy part of the human body that you sit on; "he
        deserves a good kick in the butt"; "are you going to sit
        on your fanny and do nothing?" [syn: {buttocks}, {nates},
        {arse}, {butt}, {backside}, {buns}, {can}, {fundament}, {hindquarters},
         {hind end}, {keister}, {posterior}, {prat}, {rear}, {rear
        end}, {rump}, {stern}, {seat}, {tail}, {tail end}, {tooshie},
         {tush}, {bottom}, {behind}, {derriere}, {fanny}, {ass}]
     v 1: ask for and get free; be a parasite [syn: {mooch}, {cadge},
          {grub}, {sponge}]
     2: be lazy or idle; "Her son is just bumming around all day"
        [syn: {bum around}, {bum about}, {arse around}, {arse
        about}, {fuck off}, {loaf}, {frig around}, {waste one's
        time}, {lounge around}, {loll}, {loll around}, {lounge
        about}]
     [also: {bumming}, {bummed}]
Source: WordNet® 2.0

bum 1. vt. To make highly efficient, either in time or space, often at
   the expense of clarity. "I managed to bum three more instructions out of
   that code." "I spent half the night bumming the interrupt code." In
   1996, this term and the practice it describes are semi-obsolete. In
   {elder days}, John McCarthy (inventor of {LISP}) used to compare some
   efficiency-obsessed hackers among his students to "ski bums"; thus,
   optimization became "program bumming", and eventually just "bumming". 2.
   To squeeze out excess; to remove something in order to improve whatever
   it was removed from (without changing function; this distinguishes the
   process from a {featurectomy}). 3. n. A small change to an algorithm,
   program, or hardware device to make it more efficient. "This hardware
   bum makes the jump instruction faster." Usage: now uncommon, largely
   superseded by v. {tune} (and n. {tweak}, {hack}), though none of these
   exactly capture sense 2. All these uses are rare in Commonwealth
   hackish, because in the parent dialects of English the noun `bum' is a
   rude synonym for `buttocks' and the verb `bum' for buggery.


Source: The Jargon File