Feeling one isn't as confused (9)
I believe the answer is:
sensation
'feeling' is the definition.
(sensation is a kind of feeling)
'one isn't as confused' is the wordplay.
'confused' indicates anagramming the letters.
'one'+'isnt'+'as'='oneisntas'
'oneisntas' with letters rearranged gives 'SENSATION'.
(Other definitions for sensation that I've seen before include "Feeling; thrilling person or thing" , "Feeling produced by stimulation, or dramatic news (9)" , "Scandal" , "Feeling, awareness of stimulation" , "Crowd puller" .)