Tweeter's bedtime tipple? (8)
I believe the answer is:
nightjar
'tweeter's' is the definition.
(bird known for its call)
'bedtime tipple?' is the wordplay.
'bedtime' becomes 'night'.
'tipple?' becomes 'jar' (both can informally mean an alcoholic drink).
'night'+'jar'='NIGHTJAR'
(Other definitions for nightjar that I've seen before include "Nocturnal bird of swift family" , "Noct. bird (of harsh cry)" , "flier" , "Nocturnal bird related to the swift" , "Winger" .)