Crossword clue: a dark cloud of great vertical extent charged with electricity; associated with thunderstorms

The most common answer is cumulonimbus (12 letters).

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

cumulonimbus 12 letters wn-def

a dark cloud of great vertical extent charged with electricity; associated with thunderstorms

thundercloud 12 letters wn-def

a dark cloud of great vertical extent charged with electricity; associated with thunderstorms