Is able to see a point (3)
I believe the answer is:
can
'is able to' is the definition.
(if you can do something you are able to do it)
'see a point' is the wordplay.
'see' becomes 'C' (the word for the letter, according to Chambers).
'point' becomes 'n' (North).
'c'+'a'+'n'='CAN'
(Other definitions for can that I've seen before include "has power" , "(Tin) container" , "Billy" , "let go in the US" , "John" .)