The first instance of the word terrorism was the terror of a democratically legitimated state against civilians. Its own in this case: I'm speaking of the Reign of Terror of the french revolutionary state. Since then the word terrorism was somewhat redefined. But of course not everywhere. Even you describe Hussein's actions as terror in your post.
I think it's acceptable to describe as terror that thing which kills you, wether you are someone in Bagdad 2003 who is too poor to flee to Jordan, wether you are a victim of ISIL or if you are a 16 year old male shepherd in Waziristan where there is a full legal procedure which in the end lawfully decides to kill you because you're you.
