Kind of bomb in letter people drop (5)
I believe the answer is:
aitch
This might be a double definition.
'kind of bomb' is the first definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'letter people drop' is the second definition.
'aitch' can be an answer for 'letter' (aitch is the name for the letter H). I am unsure of the 'people drop' bit.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for aitch that I've seen before include "Aspirated letter" , "8th letter of the alphabet" , "It's dropped by Cockneys" , "that I will immediately succeed" , "The letter h in full" .)