The word "squalliest" means having the most squalls or sudden gusts of wind. Some antonyms for this word could be calmest, still, serene, peaceful, tranquil or calm. These words describe a state of stillness, steady or peacefulness. When the wind is mild, the weather is calm and pleasant, and there are no abrupt changes in conditions. The opposite of squalliest is not only related to the weather but can be used in various contexts. For instance, in a chaotic or turbulent situation, calmest can be the antonym, whereas, in a noisy environment, quietest can be the antonym.