The words" assault rifles" covers any weapon in a rifle caliber that is used by a military force as their main battle rifle, not just semi-autos or full autos.
Where the definition got lost in our stupid society I do not know.
Respectfully, I must disagree.
The defintion got lost in our stupid society due to the vagaries of defintion and translation in the our English language.
IF you use the word "assault" in the most common English defintion (to attack someone or something, physically) then you are technically correct in calling any weapon used in an assault an "assault weapon", and that would include knives, rocks, crowbars, baseball bats, golf clubs, fists, etc., etc., etc... Not just firearms.
But you would not be correct in defining an "asault rifle" that way. The history of the term is well known, and has been covered many times in many places. Unfortuantely, is has also been misdefined in as many, or even more places. And it is that misdefintion that causes all the confusion.
The term "assault rifle" comes from the translation of the term "
Sturmgewehr", the name Hitler gave to the MP43/44 "machine pistols" when he approved them. They went from MP (MaschinenPistole) to Stg (Sturmgeweher) by Hitler's decree. In English, from submachinegun to assault rifle. The word "assault" is used in the military sense, assaulting/storming an objective, rather than in the common civilian sense, an attack on an individual.
From basically 1944 on, the term assault rifle as used by the military and the shooting community was defined by the general characteristics of the Stg 44. And those were, select fire, detachable magazine, and intermediate power (by WWII standards) cartridge. Most assault rifles, (but by no means all) also shared the general configuration of the Stg44, a (relatively) straight line stock, and a conspicuous pistol grip.
Over time the definition broadened a bit, but the primary features remained selective fire and an "intermediate" power cartridge.
There were a couple designs meeting those requirements before the Stg 44, but the name "assault rifle" was never applied to them before it was coined by Hitler. And there is still a small argument if they actually should be classed as assault rifles. The Russian Federov meets the mechanical defintion, but in 6.5x55mm is usually not considered an intermediate cartridge.
The accepted defintion of assault rifle was even loosly applied to semiauto versions in conversation for many years, and while not strictly accurate, we all knew what we meant.
Then comes the later half of the 1980s, and several mass shootings with AK semiautos. The media frenzy focusing the weapon and its calling them assault rifles. We tried to explain the difference, and for a short time they actually sort of listened, calling the guns "semiautomatic assault rifles".
But that was too cumbersome a sound bite, and they created the term "assault weapon". And assault weapon became codified in US law in 1994, as
semiautomatic firearms with certain cosmetic features. Not one single true assault rifle was covered by the 1994 law. ALL assault rifles had been (and still are) covered under the NFA 1934, as under US law, they are machine guns.
You can call any gun used in an assault, an assault weapon, you can consider any military arm an assault rifle. But in my opinion, you are wrong doing so.
I've killed about a dozen wild boars with mine.