Its union meets regularly with working group (6,9)
I believe the answer is:
womens institute
'group' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see a link between them that I don't see?
'its union meets regularly with working' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'working' is an anagram indicator.
The alternate letters of 'with' are 'wt'.
'its'+'union'+'meets'+'wt'='itsunionmeetswt'
'itsunionmeetswt' anagrammed gives 'WOMENS INSTITUTE'.
Can you help me to learn more?
(Another definition for womens institute that I've seen is " Group of females".)