IPA: /ˌʌnɪkˈspləʊdɪd/
KK: /ʌnɪkˈsploʊdɪd/
Describing something, usually a bomb or explosive device, that has not yet detonated or gone off.
The area was marked as dangerous due to unexploded ordnance from the war.
Unexploded → It is formed from "un-" (meaning not) and "exploded" (from Latin "explodere", meaning to drive out or burst forth). The word "unexploded" means not having burst or detonated, typically referring to ordnance that has not exploded.
Think of 'not' ('un-') having 'burst' ('explodere') — that's why unexploded means something that has not detonated.