When people refer to an AR-15 as an assault rifle.
Well isn't that what AR stands for?
)
No, AR is for the company that designed that weapon system, ArmaLite Rifle.
And a quote from Wikipedia.
In a strict definition, a firearm must have at least the following characteristics to be considered an assault rifle:[2][3][4]
It must be an individual weapon
It must be capable of selective fire
It must have an intermediate-power cartridge: more power than a pistol but less than a standard rifle or battle rifle
Its ammunition must be supplied from a detachable box magazine[5]
And it should have an effective range of at least 300 metres (330 yards)
Rifles that meet most of these criteria, but not all, are technically not assault rifles, despite frequently being called such.