No snap judgement, ironically (5,6)
I believe the answer is:
photo finish
'no' is the definition.
Both the definition and answer are singular nouns.
Maybe you can see a link between them that I can't see?
'snap judgement ironically' is the wordplay.
'snap' becomes 'photo' (I've seen this before).
'judgement ironically' becomes 'finish' (I can't explain this - if you can you should believe this answer much more).
'photo'+'finish'='PHOTO-FINISH'
Can you help me to learn more?
(Other definitions for photo finish that I've seen before include "Close ending to a race" , "Virtual dead heat in a horse race" .)