Many people, including many mainstream news sources often assume that the AR stands for “Assault Rifle”, which is entirely incorrect.
The AR actually stands for “Armalite Rifle”, Armalite being the first producer and manufacturer of the rifle designed by Eugene Stoner who was the lead engineer for the company in 1954.
The AR has also at times been said to stand for “America’s Rifle” given its prevelance in American sport shooting and culture. This is not the official designation and usually referred to as such by users and operators of the platform.
So what does AR-15 mean?
Like I mentioned above, the AR stands for “ArmaLite Rifle” and the number 15 simply stands for the model number. So AR-15 simply means “ArmaLite Rifle, Model # 15”. Though at this point , AR15 is used to describe the type of firearm instead of the specific manufacturer since the platform is now made by many more companies.