Joy wearing dress on a regular basis for family members (9)
I believe the answer is:
relations
'for family members' is the definition.
(I've seen this before)
'joy wearing dress on a regular basis' is the wordplay.
'joy' becomes 'elation' (elation is a kind of joy).
'wearing' is an insertion indicator.
'dress on a regular basis' becomes 'rs' (I can't justify this - if you can you should give a lot more credence to this answer).
'elation' going into 'rs' is 'RELATIONS'.
Can you help me to learn more?
(Other definitions for relations that I've seen before include "Family members" , "accounts" , "Kith" , "Tale-telling" , "Sex" .)