Source : Webster's Revised Unabridged Dictionary (1913)

Agnostic \Ag*nos"tic\, a. [Gr. 'a priv. + ? knowing, ? to know.]
   Professing ignorance; involving no dogmatic; pertaining to or
   involving agnosticism. -- {Ag*nos"tic*al*ly}, adv.

Agnostic \Ag*nos"tic\, n.
   One who professes ignorance, or denies that we have any
   knowledge, save of phenomena; one who supports agnosticism,
   neither affirming nor denying the existence of a personal
   Deity, a future life, etc.

Source : WordNet®

agnostic
     adj : uncertain of all claims to knowledge [syn: {agnostical}]
           [ant: {gnostic}]

agnostic
     n : a person who doubts truth of religion [syn: {doubter}]