ETYM Italian quartetto, dim. of quarto the fourth, a fourth part, from Latin quartus the fourth. Related to Quart.
1. A musical composition for four performers; SYN. quartette.
2. A set of four similar things considered as a unit; SYN. quartette, quadruplet.
3. Four people considered as a unit, especially in music; SYN. quartette, foursome.
4. Four performers or singers who perform together; SYN. quartette.
An ensemble of four musicians, or the music written for such a group. The most common type of quartet is the string quartet.