https://www.fbi.gov/investigate/terrorism#:~:text=Internatio....
International terrorism: Violent, criminal acts committed by individuals and/or groups who are inspired by, or associated with, designated foreign terrorist organizations or nations (state-sponsored).
Domestic terrorism: Violent, criminal acts committed by individuals and/or groups to further ideological goals stemming from domestic influences, such as those of a political, religious, social, racial, or environmental nature.
You can't just call anything terrorism from a legal standpoint, though many try.
Unfortunately not everyone agrees with the FBI's definition of terrorism. The FBI's definition of International terrorism depends on a list of organizations more-or-less arbitrarily assembled by politicians. Their definition of domestic terrorism is even looser.
Basically, both definitions are "violent criminal acts [waffle]". That definition is circular, because terrorism is criminal.
The word should be banned from newspapers and from political and legal discourse. Broadly speaking, it means "political activities of which we disapprove".