The word "semiautomatic" refers to a type of machinery or firearm that performs some tasks automatically, but requires a person to trigger each action.
They're typically somewhat mild, and polling on banning large categories of weapons like semiautomatic rifles is more mixed (though some recent polling still shows majorities support that). (vox.com)
My rifle was very similar to the AR -15-style semiautomatic weapon used to kill students, teachers and a coach I knew at Marjory Stoneman Douglas High School in Parkland, Fla., where I once lived. (nytimes.com)
WASHINGTON — President Trump — under pressure from angry, grieving students from a Florida high school where a gunman killed 17 people last week — ordered the Justice Department on Tuesday to issue regulations banning so - called bump stocks, which convert semiautomatic guns into automatic weapons like those used last year in the massacre of concertgoers in Las Vegas. (nytimes.com)