Definitions for kryptonˈkrɪp tɒn
Random House Webster's College Dictionary
an inert monatomic gaseous element, present in very small amounts in the atmosphere.
Ref: Symbol: Kr 2
Origin of krypton:
1895–1900; < Gk; see crypt
krypton, Kr, atomic number 36(noun)
a colorless element that is one of the six inert gasses; occurs in trace amounts in air
A chemical element (symbol Kr) with an atomic number of 36; one of the noble gases.
Origin: Neuter form of κρυπτός.
U.S. National Library of Medicine
A noble gas that is found in the atmosphere. It has the atomic symbol Kr, atomic number 36, atomic weight 83.80, and has been used in electric bulbs.