Silly one in a bomb explosion! (5)
I believe the answer is:
bimbo
'silly' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'one in a bomb explosion' is the wordplay.
'one' becomes 'i' (Roman numeral).
'in' is an insertion indicator.
'explosion' indicates anagramming the letters.
'bomb' anagrammed gives 'bmbo'.
'i' going within 'bmbo' is 'BIMBO'.
Can you help me to learn more?
(Other definitions for bimbo that I've seen before include "Attractive but empty-headed young female" , "Attractive brainless girl" , "Pretty, usually stupid, girl" , "floozie?" , "Attractive but vacant girl" .)