Point of a thorn, possibly? (5)
I believe the answer is:
north
'point' is the definition.
(north is a kind of point)
'thorn possibly?' is the wordplay.
'possibly?' is an anagram indicator (I've seen 'possibly' mean this).
'thorn' with letters rearranged gives 'NORTH'.
'of a' acts as a link.
(Other definitions for north that I've seen before include "One looking for contract" , "One of four bridge players" , "Prime Minister" , "who has to follow West's lead?" , "Former PM" .)