Being drunk, he was supple (5)
I believe the answer is:
lithe
'supple' is the definition.
(I know that supple can be written as lithe)
'being drunk he' is the wordplay.
'being drunk' becomes 'lit' (slang term).
'lit'+'he'='LITHE'
'was' is the link.
(Other definitions for lithe that I've seen before include "Of body, flexible and supple" , "Moving and bending with ease" , "Slim, graceful" , "Able to move and bend gracefully" , "Lissome, supple" .)