In Scotland, it is used to describe a girl who is really fucking ugly. Used in the same conitation as the word munter. To be munterlicious is to be uglier than someone who is a munter
"Check her out, shes munterlicious!" "gads min, state of her munterlicious face!" " no wonder your shagging him, his girlfriend is munterlicious!!"
That guys is mutterlicious, his body stays vicious, he's up in the gym just working on his fitness... he puts your girl on rock rock, they be lining down the block just to watch what he's got