Gnostic v. Agnostic

[CleanShavenJesus]

Many of us (including myself) use the terms "agnostic" as "gnostic" almost like adjectives. I call myself an agnostic atheist. But is that really how those words are used? "Gnostic" isn't even a word in that sense, it just means someone who follows the religion of Gnosticism.

Another question: most theists are gnostic, and that's a different road. But how can atheists be gnostic? I know a gnostic atheist recently joined, maybe he could respond in this thread. Nobody can know with 100% certainty that there is no God, but that's exactly what being gnostic (in our definition of the word) means.