West's bridge partner (4)
I believe the answer is:
east
'west's bridge partner' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for east that I've seen before include "bridge-player" , "Oriental lands" , "Compass point at 90 degrees" , "Bidder after North (bridge)" , "To right if facing North" .)