Remained sober, so we hear (6)
I believe the answer is:
stayed
'remained' is the definition.
('stay' can be a synonym of 'remain')
'sober so we hear' is the wordplay.
'sober' becomes 'staid' (synonyms).
'so we hear' indicates a 'sounds like' (homophone) clue.
'staid' is a homophone of 'STAYED'.
(Other definitions for stayed that I've seen before include "Continued" , "Remained or posponed" , "Didn't go" , "Withheld; remained" , "Secured; remained" .)