Definition of cumulus in English:



mass nounMeteorology
  • Cloud forming rounded masses heaped on each other above a flat base at fairly low altitude.

    ‘the high cumulus is breaking up to give a lovely summer evening’
    count noun ‘silent, moving, red-tinged cumuli’
    • ‘When the air condenses into small, lumpy, low pockets of cloud, this is cumulus.’
    • ‘The first normally is associated with vertical clouds such as cumulus.’
    • ‘These types of funnel clouds form out of large cumulus clouds or very weak thunderstorms and normally do not have the energy to reach the ground.’
    • ‘The basic cloud forms are cumulus, which are heaped clouds; stratus, which are layer clouds; and cirrus, which are wispy.’
    • ‘The azure sky above was only slightly clouded by the thick cumulus clouds that strayed away from each other, to occasionally cover up the sun's streams of rays.’


Mid 17th century (denoting a heap or an accumulation): from Latin, ‘heap’.