General English

  • noun a white or grey mass of drops of water floating in the air
  • noun a large amount of gas, smoke or dust floating in the air
  • noun something that has an unpleasant effect on a situation

General Science

  • noun a mass of water vapour or ice particles in the sky which can produce rain or snow
  • noun a mass of particles suspended in the air


  • noun a part of a computer network, which data passes through, that is either unknown or behaves unpredictably


  • noun the disturbed sediment in a liquid


  • noun a visible mass of water, ice, gas, dust or other particles in the sky

Origin & History of “cloud”

In Old English the word for ‘cloud’ was weolcen (whence modern English welkin, a poetical term for ‘sky’), which is related to German wolke ‘cloud’. At that time Old English clūd, the ancestor of cloud, meant ‘mass of rock, hill’ (it is probably related to clod). As applied to ‘clouds’, presumably from a supposed resemblance between cumulus clouds and lumps of earth or rock, it dates from the 13th century.