Added 9 October 2026 two-thirds noun Categories: Describing WordsObscure Words noun ! Definition from WordNet 3.1, Princeton University. More about two-thirds at Wordnik → Where our words come from → Two of three equal parts of a divisible whole. Related Words: one-thirdquartersthirdstwothirds2/3rdsthree-quartersthree-fourthsfive-sixthstwo-fifthsthirdone-half Back to today's word