Elopement
Elopement was the practice of running away to get married, without a formal wedding ceremony and often on the spur of the moment.
Airiam eloped, but not long thereafter lost her new husband Stephen in a shuttle crash. (DIS: "Project Daedalus")
In 2404, Lana and The Doctor eloped, something he declared was a page taken out of Tom Paris's book. Lana found the gesture romantic and claimed that her husband "Joe" had a flair for such things. (VOY: "Endgame")