Green’s Dictionary of Slang

(orig. RAF) to go away; usu. as a dismissive excl. bog off!

1943		C. Graves Seven Pilots in DSUE (1984).
1958		C. Lee diary 5 Nov. in Eight Bells & Top Masts (2001) 173: Ainslie told him to bog off. He didn’t.
1989		Viz June/July 19: Bog off! It’s not my fault!
1997		M. Walters Echo 188: Bog off, Terry. Billy can go hang for all I care.
2005		H. Mantel Beyond Black 214: Why don’t you just bog off and let me get some privacy.