Talk incessantly about North American? (4)
I believe the answer is:
yank
'american?' is the definition.
(Yank is an example)
'talk incessantly about north' is the wordplay.
'talk incessantly' becomes 'yak' (I've seen this before).
'about' is an insertion indicator.
'north' becomes 'n' ('N' can be a synonym of 'north').
'yak' enclosing 'n' is 'YANK'.
(Other definitions for yank that I've seen before include "Pull with a sudden movement" , "Pull roughly" , "Jerk, pull suddenly" , "Statesman?" , "American from the North" .)