Superlative form of stormy: most stormy.(adjective)
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Use "stormiest" in a sentence
"And while we prepare to battle around the stormiest headland in the world our situation on board grows darker."
"The chaos dominated one of the stormiest debates seen in the Greek parliament as MPs argued over a raft of strict measures demanded in return for international aid."
"It's a pillar that anchors us, even in the stormiest of times."