A disbeliever, a denier: someone who rejects or disbelieves in God as per Islam (Arabic: الله Allāh) or the tenets of Islam; or more broadly any non-Muslim.
Someone who does not conform to accepted beliefs, customs or practices.
Loosely, a Christian who does not conform to the doctrines of an established church.
A member of a church separated from the Church of England; a Protestant dissenter.
A noctuid moth (Lithophane lamda).
Not conforming to established customs, etc.