I hate to be the pedant, but UFO really does just mean unidentified flying object. Everything is a UFO before you know what it is, so this isn't even a lie.
Even if you know what it is, if you refuse to identify it, and you're the only one who can, then it's unidentified as far as everyone else is concerned.
The truth is out there... and it's relative to context
thank you
That's just the "literally" argument again. Literally doesn't mean literally, and UFO means flying saucer.
No, literally means literally, it's just picked up a figurative use, just like UFO actually means unidentified flying object, with a colloquial meaning of alien spaceship.