Clumsy Yankee should have let go earlier (7)
I believe the answer is:
unhandy
'clumsy' is the definition.
(I've seen this in another clue)
'yankee should have let go earlier' is the wordplay.
I cannot really see how this works, but
'yankee' could be 'y' (phonetic alphabet: alpha, bravo, charlie etc.) and 'y' is located in the answer.
'let go' could be 'unhand' (unhanding is a kind of letting go) and 'unhand' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for unhandy that I've seen before include "Fumbling" , "Clumsy; awkward" , "far from skilful" .)