CUMULONIMBUSES
Scrabble letter values: C3U1M3U1L1O1N1I1M3B3U1S1E1S1 = 22
Definition
CUMULONIMBUSES is the plural of CUMULONIMBUS.
noun CUMULONIMBUS: a dark cloud of great vertical extent charged with electricity.
Synonyms of CUMULONIMBUS: cumulonimbus_cloud, thundercloud