Clever message concealing its opening (4)
I believe the answer is:
able
'clever' is the definition.
(able can mean skilled or talented)
'message concealing its opening' is the wordplay.
I cannot really understand how this works, but
'message' could be 'ab' (AB is an example) and 'ab' 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 able that I've seen before include "Capable seaman" , "Fully competent" , "Competent as, say, sailor" , "Talented" , "See 21" .)