WordNet sense 1 (a colorless element that is one of the six inert gasses; occurs in trace amounts in air):

krypton

WordNet sense 2 (a communist organization formed in Cambodia in 1970; became a terrorist organization in 1975 when it captured Phnom Penh and created a government that killed an estimated three million people; was defeated by Vietnamese troops but remained active until 1999):

Khmer Rouge, Communist Party of Kampuchea, Party of Democratic Kampuchea