not on your nelly Brit. certainly not.
PHRASES originally as not on your Nelly Duff, rhyming slang for puff (i.e. breath of life).
Not on your Nelly became popular in the 1940s, meaning ‘Not on your life’, ‘no way’, ‘certainly not’ etc.
The full phrase comes from the Cockney Rhyming Slang, Not on your Nelly Duff. Now you may need to take a deep breath here (no pun intended) … how do you get from Nelly Duff to ‘not on your life’?
Well … Nelly Duff rhymes with puff which in this case means the air in your lungs or the breath of life. Hence, not on your life. Phew.
Not very plausible, I know! Cockney Rhyming slang is a twisty being.
BTW - The slang has been a bit sparse over the last few weeks but hopefully normal service will be resumed from today!