Major disagreement (5)
I believe the answer is:
minor
This could be a double definition.
'major' is the first definition.
(thesaurus)
'disagreement' is the second definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
Can you help me to learn more?
(Other definitions for minor that I've seen before include "Little-known" , "Deceptively realistic (art)" , "Smaller - child" , "Not major" , "Of less importance" .)