apostate
Concise Oxford English Dictionary © 2008 Oxford University Press:
apostate /ˈapəsteɪt/
▶noun a person who renounces a belief or principle. ▶adjective having abandoned a belief or principle.
– derivatives
apostatical adjective.
apostatical adjective.
– origin ME: from eccles. L. apostata, from Gk apostatēs ‘apostate, runaway slave’.
'apostate' also found in these Oxford entries:

