A terzanelle is a poetic

Poetry

Poetry is a form of literary art in which language is used for its aesthetic and evocative qualities in addition to, or in lieu of, its apparent meaning...

 form combining aspects of the villanelle

Villanelle

A villanelle is a poetic form that entered English-language poetry in the 19th century from the imitation of French models. The word derives from the Italian villanella from Latin villanus . A villanelle has only two rhyme sounds...

 and the terza rima

Terza rima

Terza rima is a rhyming verse stanza form that consists of an interlocking three-line rhyme scheme. It was first used by the Italian poet Dante Alighieri.-Form:Terza rima is a three-line stanza using chain rhyme in the pattern A-B-A, B-C-B, C-D-C, D-E-D...

. It is nineteen lines total, with five triplets and a concluding quatrain. The middle line of each triplet stanza is repeated as the third line of the following stanza, and the first and third lines of the initial stanza are the second and final lines of the concluding quatrain; thus, seven of the lines are repeated in the poem. The rhyme scheme

Rhyme scheme

A rhyme scheme is the pattern of rhyme between lines of a poem or song. It is usually referred to by using letters to indicate which lines rhyme. In other words, it is the pattern of end rhymes or lines...

 and stanza

Stanza

In poetry, a stanza is a unit within a larger poem. In modern poetry, the term is often equivalent with strophe; in popular vocal music, a stanza is typically referred to as a "verse"...

ic structure are as follows (a capitalized letter indicates a line repeated verbatim):

ABA'

bCB

cDC

dED

eFE

fAFA'

Or, for the alternate (couplet) ending, the final stanza is:

fFAA'

Notable examples

• Terzanelle in Thunderweather by Lewis Turco
  Lewis Turco
  Lewis P. Turco , is an American poet, teacher, and writer of fiction and non-fiction. Turco is an advocate for Formalist poetry in the United States.-Life and work:...
  
  , with a further explanation of the form