Best trivet is not in here (8)
I believe the answer is:
standout
'here' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see a link between them that I don't see?
'best trivet is not in' is the wordplay.
'best trivet' becomes 'stand' (I can't justify this - if you can you should give a lot more credence to this answer).
'is not in' becomes 'out' ('out' is the opposite to 'in').
'stand'+'out'='STANDOUT'
Can you help me to learn more?
(Other definitions for standout that I've seen before include "project" , "Persist in opposing" .)