Definitions of religious:

• noun:   a member of a religious order who is bound by vows of poverty and chastity and obedience
• adjective:   having or showing belief in and reverence for a deity

  Example: "A religious man"

• adjective:   concerned with sacred matters or religion or the church

  Example: "Religious texts"

• adjective:   extremely scrupulous and conscientious

  Example: "Religious in observing the rules of health"