sestet n the cardinal number that is the sum of five and one n six performers or singers who perform together n a set of six similar things considered as a unit n a musical composition written for six performers n a rhythmic group of six lines of verse Usage(s) Plenty of villains to choose from in the Star Wars sestet, but I'll take Palpatine, who represents political and martial power at its most toxic. Synonym(s) six 6 VI sixer sise Captain Hicks half a dozen sextet sextuplet hexad sextette