The author-illustrator 'duo' will be signing their books tomorrow.
They sang a 'duo'. [=(more commonly) 'duet']
He and his partner make/form quite a 'duo'.
(..) These two are peas in a pod, Bob, but instead of little green balls, Let's hear it once again, mc state, for your dynamic duo. Shit. My brother needs me again. Look, you know, loyalty's cool, and I admire it, and I know he's your brother. (..)2014 22 Jump Street
(..) Nothing else? They had five guys in the draft last year. I mean, Brad, this could be our shot. We're like the dynamic duo, Bro. We're like Batman and Robin. But we're both Batman. What do you want to be, like, a stockbroker? Or a cop? (..)2014 22 Jump Street