Live amid twice as much furniture (6,3)
I believe the answer is:
double bed
'furniture' is the definition.
(double bed is a kind of furniture)
'live amid twice as much' is the wordplay.
'live' becomes 'be' ('be' can be a synonym of 'live').
'amid' means one lot of letters goes inside another.
'twice as much' becomes 'doubled'.
'be' going into 'doubled' is 'DOUBLE BED'.
(Other definitions for double bed that I've seen before include "Sleeping place for two people" , "Sleeping accommodation for two people" , "Where partners relax" , "Be odd blue (anag)" .)