Buzzers a man had to boot (7)
I believe the answer is:
besides
'to boot' is the definition.
(I've seen this before)
'buzzers a man had' is the wordplay.
I cannot really understand how this works, but
'man' could be 'si' and 'si' is present in the answer.
'had' could be 'bed' ('bed' can be a synonym of 'have') and 'bed' is found within the remaining letters.
The remaining letters 'es' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for besides that I've seen before include "What's more" , "also is available" , "Apart from" , "Additionally" , "Anyway" .)