The foolish one involved in bomb making? (5)

I believe the answer is:
bimbo
'the foolish one involved in bomb making?' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'one involved in bomb making?' is the wordplay.
'one' becomes 'i' (Roman numeral).
'involved in' means one lot of letters goes inside another.
'making?' indicates anagramming the letters.
'bomb' is an anagram of 'bmbo'.
'i' placed within 'bmbo' is 'BIMBO'.
Can you help me to learn more?
(Other definitions for bimbo that I've seen before include "Pretty, usually stupid, girl" , "Attractive but vacant young woman" , "Attractive but vacant girl" , "Dolly bird" , "floozie?" .)
