cumulonimbus

/ˌkjuː.mjʊ.ləʊˈnɪm.bəs/

cumulonimbus means A cloud with a tall structure and flat base, often associated with thunderstorms.

cumulonimbus is pronounced /ˌkjuː.mjʊ.ləʊˈnɪm.bəs/.

Why “cumulonimbus” is a great word

A massive, heaped rain-cloud of great vertical development, typically heralding thunderstorms and torrential downpours. From Latin cumulus ("heap, pile") + nimbus ("rain cloud"), first recorded in English use 1885–90. Unlike the benign, cotton-ball "cumulus" or the low, dreary blanket of "stratus," the cumulonimbus is an atmospheric citadel, a booming anvil of vapor and violence. It is the bruised purple underbelly that swallows the sun, the sudden, ozone-charged wind that precedes the deluge, and the spectacular flash that splits the world in two—a colossal and temporary monument to the atmosphere's furious potential for upheaval.

Etymology

From Latin cumulus (“heap”) + nimbus (“cloud”).

noun

A cloud with a tall structure and flat base, often associated with thunderstorms.

Words closest in meaning

By meaning, not spelling — each word's AI semantic fingerprint, nearest first.

thunderhead 87% match — The top portion of a cumulonimbus cloud, which tends to be flattened or fibery in appearance, and may be indicative of thunderstorm activity. vs cumulonimbus →
cloudburst 83% match — A sudden heavy rainstorm. vs cumulonimbus →
nimbus 82% match — A circle of light; a halo. vs cumulonimbus →
asperitas 82% match — A cloud formation characterized by wavy undulations in the cloud base. vs cumulonimbus →
thundersnow 81% match — A thunderstorm accompanied by snow, rather than rain or hail. vs cumulonimbus →
waterspout 80% match — A whirlwind that forms over water, not associated with a mesocyclone of a thunderstorm (contrary to a true tornado). vs cumulonimbus →
thunderstroke 79% match — thunderbolt vs cumulonimbus →
welkin 78% match — The sky which appears to an observer on the Earth as a dome in which celestial bodies are visible; the firmament. vs cumulonimbus →