Attentive to wrong part (4)
I believe the answer is:
rapt
'attentive' is the definition.
(similar in meaning)
'wrong part' is the wordplay.
'wrong' indicates anagramming the letters.
'part' with letters rearranged gives 'RAPT'.
'to' acts as a link.
(Other definitions for rapt that I've seen before include "Enchanted in part" , "Wholly engrossed" , "Spellbound, enthralled" , "Fully absorbed" , "Gripped" .)