Agreement resulting from investing millions in firm commitment (10)
I believe the answer is:
compromise
'agreement' is the definition.
(I know that compromise is a type of accommodation)
'millions in firm commitment' is the wordplay.
'millions' becomes 'm' (abbreviation).
'in' indicates putting letters inside.
'firm' becomes 'co' (a firm is a company).
'commitment' becomes 'promise' (promise is a kind of commitment).
'co'+'promise'='copromise'
'm' inserted within 'copromise' is 'COMPROMISE'.
'resulting from investing' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for compromise that I've seen before include "Settlement" , "Agree a middle way" , "Settle by concession" , "accommodation" , "Middle course" .)