Merriam-Webster Collegiate Dictionary - religion

 noun  Etymology: Middle English religioun, from Anglo-French religiun, Latin ~-, religio supernatural constraint, sanction, religious practice, perhaps from religare to restrain, tie back — more at rely  Date: 13th century  1.  a. the state of a religious a nun in her 20th year of ~  b.  (1) the service and worship of God or the supernatural  (2) commitment or devotion to religious faith or observance  2. a personal set or institutionalized system of religious attitudes, beliefs, and practices  3. archaic scrupulous conformity ; conscientiousness  4. a cause, principle, or system of beliefs held to with ardor and faith  • ~less adjective