Meaning of DUAL in English
/ ˈdjuːəl; NAmE ˈduːəl/ adjective
[ only before noun ] having two parts or aspects :
his dual role as composer and conductor
She has dual nationality (= is a citizen of two different countries) .
The piece of furniture serves a dual purpose as a cupboard and as a table.
—see also dual-purpose ➡ note at double
late Middle English (as a noun denoting either of the two middle incisor teeth in each jaw): from Latin dualis , from duo two.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005