[also F- H-] the exclusive social set of a particular place, preceded by the
Webster’s New World College Dictionary, Fourth Edition, compiled by the
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Word origin of 'Four Hundred'popularized by C. J. Allen, New York Sun society reporter, from a remark by Ward McAllister: “There are only 400 people in New York that one really knows”; prob. from limited capacity of Mrs. J. J. Astor's ballroom