...in that colonizers use the term to justify their continued brutalization of people fighting back against oppression. It was probably on 
where I first heard the argument that it's a fairly useless term mainly used to describe any militant enemies of the west, but it occurs to me now and seems so obvious that the term "terrorist" is just a direct replacement for "savage".
It's a very racialized term masquerading as a neutral one, with a "definition" that is secondary to its actual meaning, which is to liken to a character of the Terrorist who is like a Halloween monster. It dehumanizes its target into a completely irrational monster, who you can then say did any nonsensical evil thing you can come up with and people will believe you.