One weighty measure at the bridge table (9)
I believe the answer is:
singleton
'one' is the definition.
(singleton is a kind of one)
'weighty measure at the bridge table' is the wordplay.
I cannot really see how this works, but
'measure' could be 'single' (single is a kind of measure) and 'single' is found in the answer.
'at' could be 'on' (location) and 'on' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for singleton that I've seen before include "Lone example" , "One alone" , "spinster or bachelor?" , "one diamond, perhaps" , "in club, maybe, all alone" .)