Still, grandma is admitted to men only entertainment in the end (8)
I believe the answer is:
stagnant
'still' is the definition.
('stagnant' can be a synonym of 'still')
'grandma is admitted to men only entertainment in the end' is the wordplay.
'grandma' becomes 'nan' (I've seen this before).
'is admitted to' is an insertion indicator.
'men only' becomes 'stag' (I've seen this before).
'in the end' suggests the final letters.
The final letter of 'entertainment' is 't'.
'stag'+'t'='stagt'
'nan' inserted within 'stagt' is 'STAGNANT'.
(Other definitions for stagnant that I've seen before include "Not circulating or flowing" , "Sluggish" , "Showing little activity" , "(Water) not flowing" , "Still and foul" .)