Entry 3 senses · 2 variants Webster, 1913 Forty /(fôr"ty̆)/ · For·ty · IPA /[ˈfoːtɪj]/ a. n. 01 a. Four times ten; thirty-nine and one more. 1. Four times ten; thirty-nine and one more. 02 n. The sum of four tens; forty units or objects. pl. Forties ((-tĭz)) 1. The sum of four tens; forty units or objects. 2. A symbol expressing forty units; as, 40, or xl.