I am becoming quickly bored with this, coward.
The material facts here are the stated beliefs of myself and other atheists. They are far more germane than your sloppy definitions. You can keep your sloppy definitions, but they have no bearing on the facts. Most people who identify as atheists do not claim to be certain that a deity does not exist. They do not believe that a deity exists.
You still have not sufficiently explained the difference between disbelief and an absence of belief. But it's not going to matter anyway. Even if you were not so lousy at making a semantic argument it would still only be a semantic argument.
Did you change your source for the definition of agnostic? What is your source, because I am fairly certain you dropped some of the definitions. Pretty typical for a coward.
http://www.merriam-webster.com/dictionary/agnostic
1ag·nos·tic noun \ag-ˈnäs-tik, əg-\
: a person who does not have a definite belief about whether God exists or not
: a person who does not believe or is unsure of something
Full Definition of AGNOSTIC
1
: a person who holds the view that any ultimate reality (as God) is unknown and probably unknowable; broadly : one who is not committed to believing in either the existence or the nonexistence of God or a god
2
: a person who is unwilling to commit to an opinion about something <political agnostics>
— ag·nos·ti·cism noun
I was using the etymological roots, which if you are going to make a semantic argument is helpful.
Greek agnōstos unknown, unknowable, from a- + gnōstos known, from gignōskein to know — more at know
First Known Use: 1869
But we can see in the modern definition (bold), why I (Russell, Dawkins and many other atheists) see it as meaning, coward or non committal on God or a god. Either way you are very very very agnostic.