foursome [foursomes](group of four) noun [UK: ˈfɔː.səm] [US: ˈfɔːr.səm]
quartet [quartets](group of four) noun [UK: kwɔː.ˈtet] [US: kwɔːr.ˈtet]A string quartet is rehearsing in the next room. = Un cuarteto de cuerdas está ensayando en el cuarto contiguo.
cuarteto de cuerda noun {m}
string quartet(group of four string players) noun [UK: strɪŋ kwɔː.ˈtet] [US: ˈstrɪŋ kwɔːr.ˈtet]