The phrase is often used metaphorically, to indicate strong determination, not physical immobility. He wouldn't give an inch during the debate, sticking to his point.
Pro Tip 2/3
Argument Context
Use this when someone remains strict or stubborn in an argument or negotiation. In the budget meeting, the CFO didn't move an inch on the cuts.
Pro Tip 3/3
No Compromise
It implies no willingness to compromise or make concessions. The union did not budge an inch on their demands for higher wages.