On time in public (5)
I believe the answer is:
overt
'in public' is the definition.
(I've seen this before)
'on time' is the wordplay.
'on' becomes 'over' (I've seen this before).
'time' becomes 't'.
'over'+'t'='OVERT'
(Other definitions for overt that I've seen before include "Explicit" , "Open and unconcealed" , "Open, not 1 across" , "Conspicuous" , "Open, up front" .)