I. ˈdü(-ə)l also ˈdyü-əl adjective
Etymology: Latin dualis, from duo two — more at two
Date: 1597
1. of grammatical number : denoting reference to two
2.
a. : consisting of two parts or elements or having two like parts : double
b. : having a double character or nature
• du·al·ly -ə(l)-lē adverb
II. noun
Date: 1650
1. : the dual number of a language
2. : a linguistic form in the dual