Disagree, disagreeably (5)
I believe the answer is:
clash
(Other definitions for clash that I've seen before include "Collision (of colour)" , "Conflict; be incompatible" , "Fail to fit" , "Mismatch" , "Conflict, discord" .)
I believe the answer is:
clash
(Other definitions for clash that I've seen before include "Collision (of colour)" , "Conflict; be incompatible" , "Fail to fit" , "Mismatch" , "Conflict, discord" .)