Nones
Nones is a term sometimes used to refer to those who are unaffiliated with any organized religion. This use derives from surveys of religious affiliation, in which "None" (or "None of the above") is typically the last choice. Since this status refers to lack of organizational affiliation rather than lack of personal belief, it is a more specific concept than irreligion. Polls show that in the United States, "nones" are the only "religious" group that is growing as a percentage of the population.