NOUN (1)

1. one who observes Saturday as the Sabbath (as in Judaism);


ADJECTIVE (1)

1. pertaining to the Sabbath and its observance;

The Collaborative International Dictionary of English v.0.48:

Sabbatarian \Sab`ba*ta"ri*an\, n. [L. Sabbatarius: cf. F.
   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.
      [1913 Webster]

   Note: There were Christians in the early church who held this
         opinion, and certain Christians, esp. the Seventh-day
         Baptists, hold it now.
         [1913 Webster]

   2. A strict observer of the Sabbath.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sabbatarian \Sab`ba*ta"ri*an\, a.
   Of or pertaining to the Sabbath, or the tenets of
   Sabbatarians.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Sabbatarian
    adj 1: pertaining to the Sabbath and its observance
    n 1: one who observes Saturday as the Sabbath (as in Judaism)