I remember they used to call them flying saucers. But haven’t heard that terminology used in many years.
Perhaps because not all were saucer shaped, so “UFO” was more inclusive language???
The term “flying saucer” dated back to the 1947 sighting by Kenneth Arnold. He saw unusual craft flying near Mt. Rainier in Washington state and contacted the local media. He described their motion as being like saucers on water. It was the reporters who called them “flying saucers” and the name stuck.
This article has some more detail:
https://airandspace.si.edu/stories/editorial/1947-year-flying-saucer