No bridge partners surpass uninterruptedly (3-4)
I believe the answer is:
non-stop
'uninterruptedly' is the definition.
'no bridge partners surpass' is the wordplay.
'bridge partners' becomes 'ns' (I've seen this in other clues).
'surpass' becomes 'top' (topping is a kind of surpassing).
'no'+'ns'+'top'='NON-STOP'
(Other definitions for non-stop that I've seen before include "Uninterrupted" , "continuously" , "Round-the-clock" , "Ceaseless" , "Going straight from A to B" .)