barf
     v : eject the contents of the stomach through the mouth; "After
         drinking too much, the students vomited"; "He purged
         continuously"; "The patient regurgitated the food we gave
         him last night" [syn: {vomit}, {vomit up}, {purge}, {cast},
          {sick}, {cat}, {be sick}, {disgorge}, {regorge}, {retch},
          {puke}, {spew}, {spue}, {chuck}, {upchuck}, {honk}, {regurgitate},
          {throw up}] [ant: {keep down}]
Source: WordNet® 2.0

barf /barf/ n.,v. [common; from mainstream slang meaning `vomit'] 1.
   interj. Term of disgust. This is the closest hackish equivalent of the
   Valspeak "gag me with a spoon". (Like, euwww!) See {bletch}. 2. vi. To
   say "Barf!" or emit some similar expression of disgust. "I showed him my
   latest hack and he barfed" means only that he complained about it, not
   that he literally vomited. 3. vi. To fail to work because of
   unacceptable input, perhaps with a suitable error message, perhaps not.
   Examples: "The division operation barfs if you try to divide by 0."
   (That is, the division operation checks for an attempt to divide by
   zero, and if one is encountered it causes the operation to fail in some
   unspecified, but generally obvious, manner.) "The text editor barfs if
   you try to read in a new file before writing out the old one." See
   {choke}, {gag}. In Commonwealth Hackish, `barf' is generally replaced by
   `puke' or `vom'. {barf} is sometimes also used as a {metasyntactic
   variable}, like {foo} or {bar}.


Source: The Jargon File