What is Half Inch?
1.
Cockney rhyming slang for pinch.
He half inched my wallet!
Don't you half inch anything old chap!
See
2.
To 'pinch' something
Not a form of minor physical violence or playful teastin but more to 'steal' something from someone or somewhere.
That blady teevs gone 'n' half-inched me poodle!