krypton

name

1. A fictional planet, the native world of Superman, named after the element krypton.

noun

Etymology: From Ancient Greek κρυπτός (kruptós, “hidden”) + -on, used for all noble gases.

1. The chemical element (symbol Kr) with an atomic number of 36. It is a colourless, odourless noble gas that only reacts with fluorine. It is one of the rarest gases in the Earth's atmosphere.
2. An atom of this element.