krypton
nounUK /ˈkrɪp.tɒn/
US /ˈkrɪp.tɑːn/
Krypton is a gas that you cannot see or smell and is found in very small amounts in the air.
The glowing sign in the shop window was filled with krypton gas.
OTHER MEANINGS
2. A chemical element with the symbol Kr and atomic number 36.
Krypton is listed on the periodic table between bromine and rubidium.
3. A gas used in some bright lights and photographic flashes.
The photographer used a krypton flash to light the dark room.
4. In fiction, the name of the home planet of Superman.
Superman was sent to Earth from the planet Krypton.