Atheistian 

An atheistian (atheist + Christian) is a stereotypical militant atheist who essentially treats atheism like a religion.

While atheistians will of course deny that atheism "is just another religion", they have a set of unwritten rules which they expects all members of the "atheist community" to follow

Basically a "true atheist" (according to atheistians) is a person who is one or more of the following - a communist, socialist, liberal activist, radical feminist, tree hugging environmentalist, welfare junkie, emo kid, goth, computer geek, fat fuck, virgin, homosexual, weeaboo, D&D nerd, social reject, aspie, basement dweller, or just a straight up whiney-ass loser in general who bitches about "atheist persecution" but is less tolerant than a lot of fundies.

Any atheist who doesn't fit this stereotype (ex. supporting gun ownership rights, not voting for the Socialist Party, playing sports, having a sex life, enjoying mainstream movies and music, not sporting a neckbeard, etc) is considered on par with a religious heretic by the atheistians and despised even more than Christians.

Atheist dude: I'm a big fan of Bill Maher. Anyone else here watch his show?

Atheistian 13 year old virgin: What??? Bill Maher??!? You're a fucking ignorant moron to watch that douchebag! That guy spouts anti-vaccine propaganda and he's a horrible representative for the atheist community, and you're as ignorant as he is for watching his pathetic show. STFU moron.

Atheist dude: ...uh hey dude, Bill Maher's actually a deist, not an atheist.

Atheistian 13 year old virgin: ..what what? Uh nevermind I don't care. You're a moron and you'd make a great creationist considering how fucking stupid you are. Quit giving atheists a bad name, you fucking moron. I'm going to ignore you from now on, you fucking idiot. Bye.

Atheistian by Patbenatar January 23, 2010

Atheistmas 

An annual holiday around the winter solstice that is celebrated by Atheists. For this holiday, gifts are exchanged out of goodness and out of love, and families come together. Similar to the Christian holiday, Christmas, minus the religious aspect.

Also celebrated by Agnostics.

The entire Davis family came together this year to celebrate Atheistmas. Everyone gave each other gifts and were happy to see each other.

Atheistmas by Jackson720 December 24, 2009

Atheisting 

V. The act of Not doing something stupid or pointless, and instead doing something useful or otherwise necessary . Usually because of Lack of Religion or interest.

Religious person: "Hey dude what are you Giving up for lent?"
Atheist: "Nothing man, I'll just be sitting around Atheisting by cleaning my house"

Atheisting by Angry_Atheist February 19, 2015

Atheisting 

The social networking and bonding activities of people organizing around atheism.

I have met so many like-minded friends through atheisting on Twitter!

Atheisting by threedotonefour May 18, 2010

Atheistic Morality

Doing the right thing because it is the right thing to do, not because you want to gain favor with god.

Religious Person: I gave money to charity because god would want me to.

Sane Person: I gave money to charity because some people needed it more than I did.

Religious Person: Why would you help someone for no reason?

Sane Person: it's called Atheistic Morality, learn about it.

Atheistic Morality by rational person July 24, 2012

athelstan 

The father of all cinnamon rolls. The physical embodiment of a flower crown. Too pure, too good for this world. God Himself had to take him from here and bring him to Heaven, where he frolicks in the gardens with Gyda, a fellow cinnamon roll that was also taken far too soon.

Your life will be better if you try to be more like Athelstan. However, you will die.

athelstan by hannibalsfood March 6, 2017

Atheistic 

Atheistic is the quality of being atheist. That is to believe that there is no god. Though the customary response for many logical thinkers and scientific types it falls prey to the same logic flaws of religion as it is, ultimately, a belief and has neither been proven or dis-proven.

Atheistic person: "look up there!"
Jehova's witness: *looks up at sky "there's nothing up there"
Atheistic person: "Exactly"

Atheistic by Jelly Mason August 8, 2014