Double firsts not quite achieved in academic stream? (4)
I believe the answer is:
isis
'academic stream?' is the definition.
(I've seen this before)
'double firsts not' is the wordplay.
'double' shows that letters should be duplicated.
'firsts not' becomes 'is' (I can't justify this - if you can you should give a lot more credence to this answer).
'is' doubled is 'ISIS'.
'quite achieved in' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for isis that I've seen before include "Egyptian goddess of nature" , "Jihadists" , "Revered figure" , "Egyptian goddess - Thames at Oxford" , "Wife of Osiris" .)