From the tv show
Red Dwarf, it is a commonly used insult, derived from Smegma.
1) Smeg: Exclamation of surprise not unlike fuck.
2)
Smegger: Obnoxious person
3)
Smeg head: As 2
1) Oh Smeg! What the smeggin'
smeg's he smeggin' done?!
2) I'll nut the
smegger into oblivion
3) I'm not an insubordinate man by nature. I try and respect Rimmer and all, but it's so hard because he's such a
smeg head.