Joined at four points (4)
I believe the answer is:
sewn
'joined' is the definition.
(I've seen this before)
'four points' is the wordplay.
'four' becomes 'se' (I can't explain this - if you can you should believe this answer much more).
'points' becomes 'wn' (two compass points).
'se'+'wn'='SEWN'
'at' is the link.
Can you help me to learn more?
(Other definitions for sewn that I've seen before include "Joined by stitching" , "Run up" , "Joined with stitches" , "Made as garment" , "Fastened with stitches" .)