In which belligerent speeches are delivered (3,2,5)
I believe the answer is:
war of words
'in which belligerent' is the definition.
I know nothing about this answer so I can't judge whether this works.
'speeches are delivered' is the wordplay.
I cannot really understand how this works, but
'speeches' could be 'words' (word is a kind of speech) and 'words' is present in the answer.
'are' could be 'a' (short for 'are', historical unit of measurement) and 'a' 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 war of words that I've seen before include "Slanging match" , "Bitter argument" .)