Open - and finished on time (5)
I believe the answer is:
overt
'open' is the definition.
(associated in meaning)
'finished on time' is the wordplay.
'finished' becomes 'over' (over can mean finished or ended).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'time' becomes 't' (abbreviation).
'over'+'t'='OVERT'
'and' is the link.
(Other definitions for overt that I've seen before include "Conspicuous" , "Plain to see - manifest" , "Obvious, patent" , "____ is able to be seen" , "totally visible" .)