One who disagrees or dissents; one who separates from the established religion.
Sometimes Dissident: in the kingdom of Poland, the name for Christians not part of the Roman Catholic Church.
A person who formally opposes the current political structure, the political group in power, the policies of the political group in power, or current laws.
In a manner that disagrees; dissenting; discordant.
A side, party (e.g. a team or armed force) seen as adversary, enemy etc. opposite one (or more) other(s), as in a battle or team sports competition.