Intimidate thousands in business (8)
I believe the answer is:
commerce
'business' is the definition.
(I've seen this before)
'intimidate thousands in' is the wordplay.
'intimidate' becomes 'coerce' (I can't explain this - if you can you should give a lot more credence to this answer).
'thousands' becomes 'mm' (Roman numerals).
'in' means one lot of letters goes inside another.
'coerce' going around 'mm' is 'COMMERCE'.
Can you help me to learn more?
(Other definitions for commerce that I've seen before include "The buying and selling of commodities and services" , "Trading exchanges" , "Trading activity" , "Business dealings" , "Sales and purchases of goods and services" .)