Stayed sound and sober (5)
I believe the answer is:
staid
'sober' is the definition.
(synonyms)
'stayed sound' is the wordplay.
'sound' indicates a 'sounds like' (homophone) clue.
'stayed' is a homophone of 'STAID'.
'and' is the link.
(Other definitions for staid that I've seen before include "Conventional (character)" , "Stuffy, traditional" , "Serious or sober in character" , "Unadventurous, dull" , "Calm, respectable and unadventurous" .)