Instantly but not there and then (4,3,3)
I believe the answer is:
here and now
'then' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'instantly but not there and' is the wordplay.
I cannot really understand how this works, but
'instantly' could be 'now' and 'now' is located in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
'not there' could be 'here' ('here' is the opposite to 'there') and 'here' is found within the answer.
The remaining letters 'ad' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for here and now that I've seen before include "At this time" , "on the spot" , "present" .)