noun. A verse form first used by the Provençal troubadours, consisting of six six-line stanzas and a three-line envoy. The end words of the first stanza are repeated in varied order as end words in the other stanzas and also recur in the envoy.

noun. A poem in fixed form, borrowed from the French, and said to have been invented by the Provençal troubadour Arnaut Daniel (thirteenth century).

noun. a highly structured poem consisting of six six-line stanzas followed by a tercet or envoy, for a total of thirty-nine lines.

"A sestina is a fixed verse form in which six end-words recur in a set order in six stanzas and a three-line envoi (a coda or postscript)."