Attentive in 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' is an anagram of 'RAPT'.
'in' acts as a link.
(Other definitions for rapt that I've seen before include "Fascinated in part" , "Engrossed, spellbound" , "'Transported, entranced (4)'" , "riveted" , "Part (anag.)" .)