Showing a lack of knowledge, but also not angrily getting upset (10)
I believe the answer is:
ignorantly
'showing a lack of knowledge but' is the definition.
I can't judge whether this definition defines the answer.
'not angrily getting upset' is the wordplay.
'getting upset' is an anagram indicator.
'not'+'angrily'='notangrily'
'notangrily' is an anagram of 'IGNORANTLY'.
'also' acts as a link.
Can you help me to learn more?
(Other definitions for ignorantly that I've seen before include "in ill-informed way" , "As if one doesn't know" , "In an uninformed manner" .)