Over my dead body means I will resist this with everything I have. Over my dead body, they said.
It is deliberate exaggeration and nobody takes it as a real threat. It refuses a plan rather than answering an argument, and it ends the discussion by refusing to have one.
1phraseover my dead bodyI will resist this with everything I have.
“Sell the field, over my dead body.”
over my dead body is a phrase.
Practised in Small Talk & Everyday Phrases