Bewildered teen isn't capable of understanding (8)
I believe the answer is:
sentient
'capable of understanding' is the definition.
Both the definition and answer are adjectives. Maybe they are linked in a way I don't understand?
'bewildered teen isn't' is the wordplay.
'bewildered' indicates anagramming the letters.
'teen'+'isnt'='teenisnt'
'teenisnt' is an anagram of 'SENTIENT'.
Can you help me to learn more?
(Other definitions for sentient that I've seen before include "Endowed with feeling and consciousness" , "Conscious - aware" , "having power of perception" , "Feeling, conscious" , "Having feelings" .)