1. Not known or that which is unknown; an assertion of the uncertainty of all claims to knowledge: The word agnostic was invented, or coined, by T.H. Huxley, the eminent British biologist, in his Science and Christian Tradition, published in 1870, page 21; because he felt that the existence of God was a proposition that could not be proven scientifically. So an agnostic says, in effect, "There may be a God, but as for me, I do not know."
2. A person who believes that the existence of God is unknown, but does not deny the possibility that God exists: Sherman, who was an agnostic, was not convinced that there is a God; however, he also was open to considering any evidence that would prove that God is a reality.
3. Someone who thinks it is impossible to know whether there is a God, future life, or anything beyond the material phenomena we are experiencing and who is unwilling to accept supernatural revelation: One dictionary defines an agnostic as being someone who is not, as is often held, someone who doesn’t know whether there is a God, but a person who believes it is impossible to know or to prove anything about the existence of God.