Definition of cumulonimbus in English:

cumulonimbus

noun

Meteorology
  • [mass noun] Cloud forming a towering mass with a flat base at fairly low altitude and often a flat top, as in thunderstorms.

    ‘the development of clouds from fair-weather cumulus to giant cumulonimbus’
    cu-nim
    [count noun] ‘those clouds that will build west of Baltimore late Sunday afternoon are cumulonimbi’
    • ‘A cumulonimbus has drifted over the spires of downtown, where it hangs like a vast gray anvil.’
    • ‘First, thunderstorms are birthed by cumulonimbus clouds.’
    • ‘The rising air is associated with a region of low air pressure, towering cumulonimbus clouds and rain.’
    • ‘As air rises in a large cumulonimbus or thunderhead cloud condensation occurs and all three forms of water are present.’
    • ‘The rising air cools and produces towering cumulus and cumulonimbus clouds.’

Pronunciation:

cumulonimbus

/ˌkjuːmjʊləʊˈnɪmbəs/