ignorant

a.

  1. Destitute of knowledge; uninstructed or uninformed; untaught; unenlightened.
  2. Unacquainted with; unconscious or unaware; -- used with of.
  3. Unknown; undiscovered.
  4. Resulting from ignorance; foolish; silly.

n.

  1. A person untaught or uninformed; one unlettered or unskilled; an ignoramous.