Misses relief found in Gents, commonly (7)
I believe the answer is:
maidens
'misses' is the definition.
(maiden is a kind of miss)
'relief found in gents commonly' is the wordplay.
'relief' becomes 'aid' (I've seen this in other clues).
'found in' means one lot of letters goes inside another.
'gents commonly' becomes 'mens' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'aid' inserted inside 'mens' is 'MAIDENS'.
Can you help me to learn more?
(Other definitions for maidens that I've seen before include "Females" , "More than one girl" , "Unmarried girls" , "one can't score off" , "Misses" .)