The ability to say without being silent (10)
I believe the answer is:
speechless
'silent' is the definition.
(thesaurus)
'the ability to say without' is the wordplay.
I cannot quite see how this works, but
'ability' could be 'speech' (speech is a kind of ability) and 'speech' is present in the answer.
'without' could be 'less' (I've seen this in another clue) and 'less' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'being' acts as a link.
Can you help me to learn more?
(Other definitions for speechless that I've seen before include "Dumbfounded" , "being forced to improvise?" , "Dumbstruck" , "Unable to say anything" , "Lost for words" .)