mung /muhng/ vt. [in 1960 at MIT, `Mash Until No Good';

mung /muhng/ vt.

[in 1960 at MIT, `Mash Until No Good';
sometime after that the derivation from the recursive acronym
`Mung Until No Good' became standard; but see munge] 1. To
make changes to a file, esp. large-scale and irrevocable changes.
See BLT. 2. To destroy, usually accidentally, occasionally
maliciously. The system only mungs things maliciously; this is a
consequence of Finagle's Law. See scribble,
trash, nuke. Reports from Usenet suggest
pronunciation /muhnj/ is now usual in speech, but the spelling
`mung' is still common in program comments (compare the
widespread confusion over the proper spelling of kluge).
3. The kind of beans the sprouts of which are used in Chinese food.
(That's their real name! Mung beans! Really!)

Like many early hacker terms, this one seems to have originated at
TMRC; it was already in use there in 1958. Peter Samson
(compiler of the original TMRC lexicon) thinks it may originally
have been onomatopoeic for the sound of a relay spring (contact)
being twanged. However, it is known that during the World Wars,
`mung' was U.S. army slang for the ersatz creamed chipped beef
better known as `SOS', and it seems quite likely that the word in
fact goes back to Scots-dialect munge.