Card game for four; a forerunner of bridge (5)
I believe the answer is:
whist
I believe this clue is a double definition.
'card game for four' is the first definition.
(I've seen this before)
'a forerunner of bridge' is the second definition.
(I've seen this in another clue)
(Other definitions for whist that I've seen before include "calls for silence?" , "Card-game" , "18th-century card game, the forerunner of bridge" , "Old card game" , "Trick-taking card game" .)