Yankee bet losing a mint? (7)
I believe the answer is:
perfect
'mint?' is the definition.
(similar in meaning)
'yankee bet losing a' is the wordplay.
I cannot quite see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for perfect that I've seen before include "textbook, > superb" , "Polish" , "Without fault or defect" , "Without blemish" , "Ideal, without flaw" .)