A History of Short Words

From the New York Times Crossword Puzzle

UFO

Wed, 29 Mar '23
Supposed Roswell crasher
Sun, 5 Mar '23
It might turn out to be a drone
Fri, 10 Feb '23
Klaatu's vehicle in "The Day the Earth Stood Still"
Tue, 31 Jan '23
Mysterious sky sighting
Thu, 4 Aug '22
Dish seen around the world?
Tue, 25 Jan '22
Peculiar light in the sky, in brief
Sun, 17 Oct '21
Ship for 28-Across
Thu, 14 Oct '21
World traveler?
Thu, 4 Mar '21
Space oddity
Wed, 24 Feb '21
What Venus is sometimes mistaken for, due to its brightness
Sat, 13 Feb '21
Subject of many a conspiracy theory