ancient astronaut

Noun

 * 1) Any of the extraterrestrial beings that, according to the pseudoscientific belief of paleocontact, visited Earth in the distant past, influencing human culture, technology, or religion.
 * 2) * 2001, Charles M. Wynn, Arthur W. Wiggins, Sidney Harris, Quantum leaps in the wrong direction: where real science ends-- and pseudoscience begins, Joseph Henry Press, page 58:
 * Is it possible for scientists to demonstrate that ancient astronauts have ever been here? No.

Translations

 * French: ancien astronaute
 * Portuguese: antigo astronauta