Hole in the wall used by the hat check girl (5)
I believe the answer is:
hatch
'check girl' is the definition.
'hatch' can be an answer for 'check' (thesaurus). I am not sure about the 'girl' bit.
'hole in the wall used by the hat' is the wordplay.
'hole in the wall' becomes 'ch' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'used by' says to put letters next to each other.
'ch' put after 'hat' is 'HATCH'.
Can you help me to learn more?
(Other definitions for hatch that I've seen before include "Brood" , "Enter the world" , "Access opening" , "Of young bird or fish, emerge from egg" , "Come up with" .)