Plain net (5)
I believe the answer is:
clear
I believe this clue is a double definition.
'plain' is the first definition.
(similar in meaning)
'net' is the second definition.
(I know that net can be written as clear)
(Other definitions for clear that I've seen before include "Easily understood" , "beyond doubt" , "Open; not cloudy" , "Not obstructed" , "Leap over" .)