Stayed strangely unmoved (6)
I believe the answer is:
steady
'unmoved' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?
'stayed strangely' is the wordplay.
'strangely' is an anagram indicator.
'stayed' is an anagram of 'STEADY'.
Can you help me to learn more?
(Other definitions for steady that I've seen before include "Pull yourself together" , "Uniform" , "Ovisac of some marine creatures" , "Not liable to fluctuations" , "Not wavering" .)