Patent finished before end of night (5)
I believe the answer is:
overt
'patent' is the definition.
(both can mean obvious)
'finished before end of night' is the wordplay.
'finished' becomes 'over' (over can mean finished or ended).
'before' means one lot of letters go next to another.
'end of' indicates one should take the final letters.
The last letter of 'night' is 't'.
'over'+'t'='OVERT'
(Other definitions for overt that I've seen before include "Plain and obvious" , "Open, up front" , "Clear" , "Not concealed - public" , "not disguised" .)