:barf: /barf/ [from mainstream slang meaning `vomit']
1. interj. Term of disgust. This is the closest hackish
equivalent of the Val\-speak "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}.
-- The AI Hackers Dictionary