a synonym for fucked up or fucked. The word was invented in New Zealand when there was a major earthquake in Christchurch. People realized they couldn't keep saying "this is fucked as" or "everything is fucked". So they came up with "munted as" or "munted".
"this is road is munted as" or "look at that house, its munted".
you can also use it to describe someones face after a fight, "man you look munted as mate"