Forbids a bachelor to go to the Poles (4)
I believe the answer is:
bans
'forbids' is the definition.
(banning is a kind of forbiding)
'a bachelor to go to the poles' is the wordplay.
'a bachelor' becomes 'ba' (the qualification: Bachelor of Arts).
'to go to' says to put letters next to each other.
'the poles' becomes 'ns' (North and South poles).
'ba'+'ns'='BANS'
(Other definitions for bans that I've seen before include "Forbids" , "Officially prohibits" , "Prohibiting decree" .)