zealot
Concise Oxford English Dictionary © 2008 Oxford University Press:
zealot /ˈzɛlət/
▶noun
- 1 a fanatical and uncompromising follower of a religion or policy.
- 2 (Zealot) a member of an ancient Jewish sect aiming at a world Jewish theocracy and resisting the Romans until ad 70.
– derivatives
zealotry noun.
zealotry noun.
'zealot' also found in these Oxford entries:

