Understood to have made the grade (8)
I believe the answer is:
gathered
'understood' is the definition.
('gather' can be a synonym of 'understand')
'made the grade' is the wordplay.
'made' indicates an anagram.
'the'+'grade'='thegrade'
'thegrade' with letters rearranged gives 'GATHERED'.
'to have' is the link.
(Other definitions for gathered that I've seen before include "Picked up" , "Accumulated, brought together" , "Collected in one place and concluded" , "Concluded from evidence" , "Got together - tucked in" .)