A lack-of-belief-atheist or "lobatheist" is a pejorative for a person who claims the definition of an atheist should be anyone who has the psychological state of lacking a belief in god. This is in addition to the conventional definition of an atheist of holding the belief god(s) does not exist.
They typically insist one is an atheist simply if they are not a theist, even if that person is unable or unwilling to definitively answer the proposition there is at least one god. To quote Aron Ra: "An agnostic is someone who does not know they are really an atheist." 
Lobatheists often, but not always, assert this for political reasons. Such as bolstering 'atheist' numbers in polls. Also to make people more comfortable calling themselves atheists and to popularize being an atheist. It is obvious that many lobathiests don’t actually care what other people believe or what their positions are, only what people don’t actively believe in.
As lobatheist is not a response to theism direct or indirect; it is possible for a theist to be a lobatheist.
Many non theist lobatheists are lacktheists, although there are a number of true atheists as well. There are also some agnostics who would prefer to be defined as an atheist and are too pedantic over the definition to just call themselves an atheist without also trying to redefine the word. Presumably because Aron Ra told them they are an atheist, and is the authority on how an atheist should be defined as Aron himself is a prominent atheist.
Lobatheists often assert their proposition aggressively. Furthermore, when confronted with arguments against their definition, the lobatheist will often resort to fallacious arguments to defend their proposition, or citing papers that refute their own position. Lobatheists may also become extremely upset or angry that people are against the use of their definition, even in reasonable conversation. A lobatheist would define all of the above positions with the exception of a theist as an atheist. Some of the more aggressive lobatheists may also demand that everybody who is not a theist define themselves as an atheist. The American Atheists strongly push for lobatheism.
The lobatheist definition of an atheist is almost identical to a non-theist, except they include theological non cognitives and agnostics as well.
"A-theism. The a in atheism MUST ALWAYS mean 'without'!"
Notable Lobatheists: Edit