It won't let you come straight in (9,4)
I believe the answer is:
revolving door
'it wont let you come straight in' is the definition.
The definition suggests a singular noun which matches the answer.
'it wont let you come straight in' is the wordplay.
I cannot really see how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found within the answer.
'come' could be 'do' (synonyms) and 'do' is found in the answer.
'in' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for revolving door that I've seen is " Rotating entrance".)