stopping or ending a process implies that the process was asked to stop... killing a process means you say "fuck you"
And yet, the "kill" command is used for all 32-odd types of signals, not just SIGKILL
It's a hardware term not a software term, but I'm fond of "mollyguard." It's the plastic cover over a button, so pressing it it a two-step process, and the idea extended to other two-step processes for doing something you want people to think before doing. And it was named after one computer operator's daughter whom he'd bring to work, and liked pressing red shiny things.