Couple with no last make rotten cobblers (7)
I believe the answer is:
twaddle
'couple' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'with no last make rotten cobblers' is the wordplay.
I cannot really understand how this works, but
'with' could be 'w' (abbreviation) and 'w' is found in the answer.
'rotten' could be 'addle' (I've seen this before) and 'addle' is found in the answer.
A single letter 't' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for twaddle that I've seen before include "Balderdash" , "Trivial/foolish speech" , "Bull" , "Moonshine" , "Senseless talk" .)