Superlative form of square: most square.(adjective)
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Use "squarest" in a sentence
""Old Captain Somers," he called him -- "the finest, squarest, noblest man I ever sailed under, sir.""
"Thousands of miles away from California's borders, in one of the squarest, lamest and most uptight cities in the nation (Washington, D.C.), law students at one of America's most prestigious universities are making the "intelligent" argument for legalization."
"Even the “squarest” girl found herself transporting drugs at least once, if not on a regular basis."