du·al 
/ˈdu:wəl, Brit ˈdju:wəl/ adjective
always used before a noun /ˈdu:wəl, Brit ˈdju:wəl/ adjective 1 : having two different parts, uses, etc.
▪ the dual purpose of the study ▪ The song's lyrics have a dual [=(more commonly) double] meaning. ▪ a dual function ▪ She held dual citizenship in France and the United States. [=she was a citizen of both countries] 2 : having two of something
▪ Our car has dual air bags. [=has two air bags] ▪ She pursued dual careers in music and acting. ▪ families with dual incomes
▪ the dual purpose of the study ▪ The song's lyrics have a dual [=(more commonly) double] meaning. ▪ a dual function ▪ She held dual citizenship in France and the United States. [=she was a citizen of both countries]
▪ Our car has dual air bags. [=has two air bags] ▪ She pursued dual careers in music and acting. ▪ families with dual incomes
— du·al·ly adverb
▪ He is dually certified to teach math and science.
▪ He is dually certified to teach math and science.
