What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
Mineralogy. Any of various minerals or ores containing uranium; (in later use) specifically any of a group of minerals which are phosphates and arsenates of uranium (in the form of the cation uranyl) and another metal.
Late 18th century (in an earlier sense). From German Uranit from Uranus (then newly discovered) + -it. Compare French uranite.