One of Joonas's old Qs. has made a welcome return: Is there a Latin euphemism for going to the toilet?. This brought to mind the fatuous things we say about death: "He's passed over."; "He's passed on."; currently in vogue; "He's passed."; this could be, "He's (the) past." reflecting American gangster-vernacular, "He's history.".
Much of this is driven by embarrassment (and fear of death), especially when talking to the bereaved--what do you say?
I'm just as bad, using Cockney (London) rhyming-slang, "He's brown-bread.".
Did the Romans use euphemisms for "death" & "dying"?