1 very common adjective (1) noun (1) adjective 1. used of a single unit or thing; not two or more “ane” Synonymsoneiane Similarcardinal noun 1. the smallest whole number or a numeral representing this number “he has the one but will need a two and three to go with it” “they had lunch at one” SynonymsoneIacesingleunity Related words Broader terms digit Narrower terms monadsingleton WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.