Customary, commonly approved (8)
I believe the answer is:
accepted
I believe this is a double definition.
'customary' is the first definition.
(I've seen this before)
'commonly approved' is the second definition.
(I've seen this before)
(Other definitions for accepted that I've seen before include "Established" , "Conventional -- customary" , "Received; tolerated" , "Tolerated; believed to be correct" , "Received willingly" .)