Whist drive held at the United Nations at this time (7)
I believe the answer is:
whitsun
'whist drive held at the united nations at this time' is the definition.
The answer and definition can be both related to time as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'united nations at this time' is the wordplay.
'united nations' becomes 'UN' (abbreviation).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'this time' becomes 'whits' (I can't explain this - if you can you should give a lot more credence to this answer).
'un' after 'whits' is 'WHITSUN'.
Can you help me to learn more?
(Other definitions for whitsun that I've seen before include "Pentecost season" , "Period seven weeks after Easter" , "Holy Spirit festival" , "Feast" , "holiday?" .)