lord and master
noun
1
the backside, the buttocks. Rhyming slang, extending the sequence 'plaster' – PLASTER OF PARIS – ARIS – ARISTOTLE – BOTTLE; BOTTLE AND GLASS – ARSE. Sometimes seen in the abbreviated form of 'lord' UK, 1998.
2
a plaster (a first aid dressing). Rhyming slang UK, 1998