Fresh beer right on time (5)
I believe the answer is:
alert
'fresh' is the definition.
(thesaurus)
'beer right on time' is the wordplay.
'beer' becomes 'ale' (I've seen this before).
'right' becomes 'r' (common abbreviation).
'on' means one lot of letters go next to another.
'time' becomes 't'.
'ale'+'r'+'t'='ALERT'
(Other definitions for alert that I've seen before include "Vigilant - warning" , "Watchful, quick-thinking" , "Watchful; warning" , "alarm" , "sharp-witted" .)