Throw in the towel, having trouble dropping European in fight (3,3)
I believe the answer is:
bow out
'throw in the towel having trouble dropping' is the definition.
I can't judge whether this definition defines the answer.
'european in fight' is the wordplay.
'european' becomes 'ow' (I can't explain this - if you can you should believe this answer much more).
'in' means one lot of letters goes inside another.
'fight' becomes 'bout' (as in a bout in boxing).
'ow' going within 'bout' is 'BOW OUT'.
Can you help me to learn more?
(Other definitions for bow out that I've seen before include "Withdraw from a situation" , "Retire gracefully" , "What a string player often gets" , "Retire from the scene with bodily gesture of acknowledgement?" , "Exit; retire" .)