I want to know what "AR" realy stands for. Ive hear automatic rifle, aramalite rifle, and others. What does it realy stand for?

Armalite Rifle model 15.

Eugene Stoner founded the original ArmaLite. It is ArmaLite Rifle 15.

Historical correction:

Armalite existed before Lord Stoner went to work for them. Armalite was a division of Fairchild Aircraft and was started by George Sullivan.

In fact, George Sullivan was at a local range shooting a prototype AR1 (light weight bolt-action rifle with steel lined aluminum barrel), when he came across a hobbyist gunsmith named Eugene Stoner. Stoner was testing his newly developed M6 rifle (.30-06 semi-auto rifle with an aluminum receiver and that has similar features to an M14 and a Johnson 1941). Sullivan admired Stoner's craftsmanship and offered him a job. The rest is history.

Just thought you'd like to know the story.

Lord Stoner

Lord Stoner is correct.  There are several 'AR's that are neither 'Automatic' nor 'Rifles'.

AR is for [b]AR[/b]malite - nothing more, nothing less.

From the FAQ at the Maryland AR-15 Shooters Website: