Sod off
What is the origin of the British expression 'Sod off'?
Sod and bugger are both slang terms for sodomite. 'Sod off' is a mid 20th century term which parallels the early 20th century 'bugger off'.
It is an example of the traditional British-English way of forming 'oaths'. Take any profanity and add 'off' to make an impolite way of saying 'go away', or add 'up' to form a phrase meaning a mistake.
(Though the second does not apply to the word 'piss'.)
DFG