Even I, perhaps, could be afraid (12)
I believe the answer is:
apprehensive
'afraid' is the definition.
('apprehensive' can be a synonym of 'afraid')
'even i perhaps could be' is the wordplay.
'could be' indicates an anagram.
'even'+'i'+'perhaps'='eveniperhaps'
'eveniperhaps' anagrammed gives 'APPREHENSIVE'.
(Other definitions for apprehensive that I've seen before include "Uneasy, anxious" , "Feeling anxiety or fear about future events" , "Seven happier (anag.)" , "Fearful, anxious" , "Worried" .)