"Mass shooting" means whatever the person using the term wants it to mean; the only real requirement for the term is that an even involves a firearm and 2 or more people.
As such, the anti-gun troglodytes, in another example of how the (D)ishonest prey on the emotions of the ignorant, have lowered the bar as far as they think they can so as to encompass as many shootings as possible.
In doing so, they dilute the terms to the point where it has no real meaning.
"Mass shootings" in America, 2022:
"Mass shootings" as defined by:
Mass Shootings in 2022 | Gun Violence Archive
Total mass shootings:
636
Total killed, mass shootings:
660
Average killed per shooting:
1.04
Total murders in US, 2022: ~10500
% mass shootings: ~
6.29%
Mass shootings in the US represent less than 6.5% of the murders in the US
That's not the impression you get from the news, eh?
There's a reason for that.