Take it – it could be supreme (7)
I believe the answer is:
presume
'take it' is the definition.
(I've seen this before)
'could be supreme' is the wordplay.
'could be' is an anagram indicator.
'supreme' is an anagram of 'PRESUME'.
'aeur it' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for presume that I've seen before include "Take to be the case" , "Suppose without proof" , "Believe" , "Take for granted" , "Suppose; take liberties" .)