What is "jack mormon"

n. A member of the Church of Jesus Christ of Latter-day Saints who believes in the premises of the faith but does not adhere to the church's standards of conduct, such as its prohibition of the consumption of alcohol, coffee(,) and tobacco.

The term Jack Mormon is a slang term originating in nineteenth-century America. It was originally used to describe a person who was not a baptized member of the Church of Jesus Christ of Latter Day Saints but who was friendly to Church members and Mormonism, sympathized with them, and/or took an active interest in their belief system. Sometime in the early- to mid-twentieth century, however, the term began to refer to an individual deemed by adherents of The Church of Jesus Christ of Latter-day Saints (LDS Church) to be an inactive or lapsed member of the LDS Church who, despite his personal religious viewpoint, maintained good relations with and positive feelings toward the LDS Church.