Sabbatarian
Sabbatarian , noun
[Latin Sabbatarius: compare French sabbataire. See Sabbath.]
1.
One who regards and keeps the seventh day of the week as holy, agreeably to the letter of the fourth commandment in the Decalogue.
There were Christians in the early church who held this opinion, and certain Christians, esp. the Seventh-day Baptists, hold it now.
2.
A strict observer of the Sabbath.
Sabbatarian , adjective
Of or pertaining to the Sabbath, or the tenets of Sabbatarians.