Agnostic

1. noun

   a person who claims that they cannot have true knowledge about the existence of God (but does not deny that God might exist)

2. noun

   someone who is doubtful or noncommittal about something

   Similar: doubter

3. adjective

   of or pertaining to an agnostic or agnosticism

4. adjective

   uncertain of all claims to knowledge

   Similar: agnostical