Excellent explanation of what "agnostic" and "atheist" really mean
Agnosticism deals with one's claim to knowledge on a subject; atheism describes one's lack of belief in deities. They are not mutually exclusive terms. If you don't claim to know whether or not gods exist, regardless of your belief or lack thereof, you are agnostic. Agnostic simply means "without knowledge." You can be an agnostic atheist (I don't know, but I don't believe in gods), or an agnostic theist (I don't know, but I do believe in god/s). A gnostic atheist/theist would claim to know their position is true. A gnostic theist holds the position, "I believe in god and I know he exists". A gnostic atheist is the opposite, "I know there is no god.
via atheistrev.com
Finally a succinct and understandable definition of these terms.
