One serving has disposition to submit (4,2)
I believe the answer is:
give in
'submit' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for give in that I've seen before include "Yield, accede" , "Surrender, yield" , "Cease arguing; submit" , "Yield, submit" , "Surrender informally" .)