Main definitions of K2 in US English:

: K21K22

K21

proper noun

  • The highest mountain in the Karakoram range, on the border between Pakistan and China. The second highest peak in the world, it rises to 28,250 feet (8,611 m). It was discovered in 1856 and named K2 because it was the second peak to be surveyed in the Karakoram range. It was formerly known as Mount Godwin-Austen after Col. H. H. Godwin-Austen (1834–1923), who first surveyed it.

    Also called Dapsang

Main definitions of K2 in US English:

: K21K22

K22

noun

informal
  • A type of synthetic marijuana.

    ‘many stores that did a brisk business in fake pot had gotten around the laws by making slight changes to K2's chemical formula’

Origin

Early 21st century: origin unknown.