Not intoxicated (5)
I believe the answer is:
sober
'not intoxicated' is the definition.
('sober' is the opposite to 'intoxicated')
This is the entire clue.
(Other definitions for sober that I've seen before include "Temperate" , "On the wagon" , "Sensible - clear-headed" , "Dignified and serious" , "Sedate and rational" .)