Viewed, understood (3)
I believe the answer is:
saw
I believe this clue is a double definition.
'viewed' is the first definition.
('see' can be a synonym of 'view')
'understood' is the second definition.
('see' can be a synonym of 'understand')
(Other definitions for saw that I've seen before include "Wise old saying about a tool" , "Old saying with teeth" , "Viewed; maxim" , "Old saying for woodcutter" , "Wise saying or cutting tool" .)