Thunberg say outrageously great (5)
I believe the answer is:
greta
'thunberg' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's an association between them I don't understand?
'outrageously great' is the wordplay.
'outrageously' is an anagram indicator (I've seen this in other clues).
'great' is an anagram of 'GRETA'.
'say' acts as a link.
Can you help me to learn more?
(Other definitions for greta that I've seen before include "- Garbo, Swedish actress" , ".....Garbo, who wanted to be alone" , "The familiar Ms Garbo, solitary film star" , "Miss Garbo" , "Woman" .)