Returns because the wrens inside must be freed (7)
I believe the answer is:
answers
'returns' is the definition.
(I've seen this before)
'because the wrens inside must be freed' is the wordplay.
I cannot really understand how this works, but
an anagram of 'wrens' is 'nswer' which is located in the answer.
'because' could be 'as' (I've seen this in other clues) and 'as' is present in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for answers that I've seen before include "Responds" , "keys" , "Replies" , "Responses; solutions" , "Returns" .)