schismatic
Concise Oxford English Dictionary © 2008 Oxford University Press:
schismatic /sɪzˈmatɪk, skɪz-/
▶adjective characterized by or favouring schism. ▶noun chiefly historical (especially in the Christian Church) a person who promotes schism.
– derivatives
schismatically adverb.
schismatically adverb.
'schismatic' also found in these Oxford entries:

