In one hand, old bridge partners get clubs (5)
I believe the answer is:
irons
'clubs' is the definition.
(I know this)
'in one hand old bridge partners' is the wordplay.
'in one' becomes 'i' (Roman numeral. I am not sure about the 'in' bit.).
'hand' becomes 'R' (abbreviation for right, as in the right-hand side).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'bridge partners' becomes 'ns' (North and South are team-mates in bridge).
'i'+'r'+'o'+'ns'='IRONS'
'get' acts as a link.
(Other definitions for irons that I've seen before include "English actor" , "Golf clubs with metal heads" , "Golfclubs with metal hands" , "One might have too many in the fire" , "cuffs" .)