The problem is, the usage of these terms is somewhat inconsistent amongst different speakers of the language. This is partly due to religio-political considerations-if ‘atheist’ is defined as someone who firmly believes that there are no deities, and ‘agnostic’ as someone who totally suspends judgment on the matter, then there aren’t too many of either …
But that leaves some issues with non-categorized belief systems. I don’t believe in any deity I’ve ever heard described (by anyone other than a few pantheists, whose ‘deity’ I don’t agree rightly falls into that category). And I don’t think the general term s ‘deity’ and ‘god’ are well-defined enough to make a blanket statement about their existence or non-existence (according to some definitions, the idea is incoherent or clearly contradictory to observed facts, but according to others, my lack of belief is simply due to lack of positive evidence). But according to the definitions in the paragraph above, I am neither an agnostic nor an atheist. To which I stick out my tongue and describe myself as an agnostic atheist anyway.