Apostate's nervous twitch after present (7)
I believe the answer is:
heretic
'apostate's' is the definition.
(thesaurus)
'nervous twitch after present' is the wordplay.
'nervous twitch' becomes 'tic' (I've seen this before).
'after' says to put letters next to each other.
'present' becomes 'here' ('here' can be similar in meaning to 'present').
'tic' put after 'here' is 'HERETIC'.
(Other definitions for heretic that I've seen before include "person not acting in good faith?" , "Cheer it (anag.)" , "contrarian" , "Misbeliever" , "Non-believer" .)