Bully lost thousands from commerce (6)
I believe the answer is:
coerce
'bully' is the definition.
(I've seen this in another clue)
'thousands from commerce' is the wordplay.
'thousands' becomes 'mm' (Roman numerals).
'from' is a deletion indicator.
'commerce' with 'mm' taken out is 'COERCE'.
'lost' is the link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for coerce that I've seen before include "Railroad" , "Make or compel" , "Persuade using threats" , "'Force, pressurise (6)'" , "Persuade by threatening" .)