They disagree on a number of points (4)
I believe the answer is:
noes
'they disagree' is the definition.
The definition suggests an adverb but the answer is not.
'on a number of points' is the wordplay.
'on' says to put letters next to each other.
'a number' becomes 'n' (n can represent any number).
'of' becomes 'o''.
'points' becomes 'es' (two compass points).
'n' put next to 'o' is 'no'.
'no'+'es'='NOES'
Can you help me to learn more?
(Other definitions for noes that I've seen before include "more than one refusal" , "Those who vote against" , "Negative voters'" , "Votes against a motion" , "Opponents" .)