Remained sober, we hear (6)
I believe the answer is:
stayed
'remained' is the definition.
('stay' can be a synonym of 'remain')
'sober we hear' is the wordplay.
'sober' becomes 'staid' (synonyms).
'we hear' indicates a 'sounds like' (homophone) clue.
'staid' sounds like 'STAYED'.
(Other definitions for stayed that I've seen before include "Secured; remained" , "Stuck around" , "Continued" , "Remained, propped up" , "having support" .)