Made sure of five out of seven (4)
I believe the answer is:
seen
'made sure' is the definition.
The definition and answer can be both related to thinking as well as being past participle verbs.
Perhaps you can see an association between them that I can't see?
'five out of seven' is the wordplay.
'five' becomes 'V' (Roman numeral).
'out of' is a deletion indicator.
'seven' with 'v' removed is 'SEEN'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for seen that I've seen before include "Distinguished" , "Espied" , "Met - understood" , "Sighted" , "Spotted" .)