duo 
/ˈdu:woʊ, Brit ˈdju:wəʊ/ noun
plural du·os /ˈdu:woʊ, Brit ˈdju:wəʊ/ noun [count] 1 : two people who perform together, are usually seen together, or are associated with each other
▪ The comedy duo will perform tonight. ▪ The author-illustrator duo will be signing their books tomorrow. ▪ He and his partner make/form quite a duo. 2 : a piece of music that is performed by two musicians
▪ They sang a duo. [=(more commonly) duet]
▪ The comedy duo will perform tonight. ▪ The author-illustrator duo will be signing their books tomorrow. ▪ He and his partner make/form quite a duo.
▪ They sang a duo. [=(more commonly) duet]
