I do so hope this never happens. “Gunman” is a descriptive word: man with gun. If women started getting into it, I guess they’d start saying “gunperson”.
“Terrorist”, on the other hand, describes only the opinion of the person using the word, which, chances are, I don’t give a shit about. In current usage it means “Person unaffiliated with any recognized nation-state or its subdivisions who kills people for reasons I don’t approve of.” Shooting up an abortion clinic is, to people like you and me, a disapproved motive for killing people, so we can go with “terrorist”, but many fundamentalist Christians, while they won’t say so publicly, will mutter in their hearts about how he’s “one of God’s warriors.” Onward Christian Soldiers, and all that. Similarly, Obama can send drones to blow up houses full of children, but he’s not a “terrorist” because, oh well, that’s just collateral damage, and didn’t he get one of those Islamist kingpins in the process?And cops can blow away black people at traffic stops because, well, they were black, so they were probably hoodlums.
The word has nothing whatsoever to do with “terror” because terror is a response to an action, not the action itself. You can’t be a “terrorist” if you don’t inspire terror. I myself am not terrorized at all by these religionists because … here’s the thing … I plan to die. Although I realize it’s no more statistically likely for me to die at the hands of a gunman than to be crushed or beheaded in a highway accident, if I did happen to find myself looking down the barrel of a gun and into the deranged eyes of someone believing there is an invisible man in the sky, I’m pretty sure my reaction would be one of relief: “Ah, what good luck! I’m gonna be spared all that time lying in a bed with terminal cancer, attended to by hospice nurses and orderlies!”
Same goes for cops and for politicians with drones: you come and get me when you’re ready, meantime I’m gonna have fun and enjoy the life I’ve got.