Bellowing in the 1920s, perhaps? (7)
I believe the answer is:
roaring
'bellowing' is the definition.
(I know that bellowing can be written as roaring)
'in the 1920s perhaps?' is the wordplay.
I cannot quite understand how this works, but
'in' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for roaring that I've seen before include "Emphatic (success)" , "Do a - trade, - forties" , "Bellowing, hollering" , "The Lion's part, nothing but this (MND)" , "Sounding as a lion" .)