Affairs where cats entertain ladies regularly (8)
I believe the answer is:
liaisons
'affairs' is the definition.
('liaison' can be a synonym of 'affair')
'cats entertain ladies regularly' is the wordplay.
'cats' becomes 'lions' (lion is a kind of cat**).
'entertain' means one lot of letters goes inside another.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'ladies' are 'ais'.
'lions' enclosing 'ais' is 'LIAISONS'.
'where' is the link.
(Other definitions for liaisons that I've seen before include "Romance or mediations" , "Secret relationships, often illicit" , "Alison is embroiled in affairs" , "Affairs or mediations" , "Illicit love affairs" .)