A versatile and generic term of non-endearment, can be used as an expletive, or as a word to describe someone or something unpleasant. Example: 1. Why don't you smeg off to where you came from. 2. My mouth always feels a bit smeggy in the morning.
SMEG
Meaning of SMEG in English
Slang English vocab. Английский сленговый словарь. 2012