What is the X in X-mas?
1769, short for stella polaris, Modern Latin, literally "the pole star" (see polar). The ancient Greeks called it Phoenice, "the Phoenician (star)," because the Phoenicians used it for navigation, though due to precession of the equinoxes it was not then the pole star. Also see pole (n.2). The Old English word for it was Scip-steorra "ship-star," reflecting its importance in navigation. As the name of a U.S. Navy long-range submarine-launched guided nuclear missile, it dates from 1957.
A bright star at the end of the handle of the Little Dipper in the constellation Ursa Minor. Polaris is 1° from the north celestial pole, and it remains in the same location in the sky all year, making it a useful navigation tool. Polaris is actually a double star with a faint companion star and has an apparent magnitude of 2.04. Also called North Star. Scientific name: Alpha Ursae Minoris.