Terza rima (/ˌtɛərtsə ˈriːmə/, also US: /ˌtɜːr-/,[1][2][3] Italian: [ˈtɛrtsa ˈriːma]; lit. 'third rhyme') is a rhyming verse form, in which the poem, or each poem-section, consists of tercets (three-line stanzas) with an interlocking three-line rhyme scheme: The last word of the second line in one tercet provides the rhyme for the first and third lines in the tercet that follows (ABA BCB CDC). The poem or poem-section may have any number of lines (not divisible by 3), but it ends with either a single line or a couplet, which repeats the rhyme of the middle line of the previous tercet (YZY Z or YZY ZZ).[4]
Terza rima was invented early in the fourteenth century by the Italian poet Dante Alighieri for his narrative poem the Divine Comedy, which he set in hendecasyllabic lines. In English, poets often use iambic pentameter. Terza rima is a challenging form for a poet, and it did not become common in the century following its invention. The form is especially challenging in languages that are inherently less rich in rhymes than Italian.[5]
Terza rima can give to the verse the effect of rhymes surging the narrative forward. It can also give a sense of continuity to the verse — the rhymes are woven together, and a reading of a canto cannot be stopped without the sense of something (the rhyme scheme) broken or unfinished. The rhymes of terza rima add the effect of echo and expectation — as a line is read there is the sense it will soon be followed by a rhyme that will complete the rhyme scheme.[6] Terza rima can lend a sense of strength and solidity to the story or the poem — each tercet, though brief, has enough length to contain a complete thought or expression, that can be considered independently. Tercets are like the building blocks of the poem or canto, and the interwoven rhyme serves as the cement that binds them together.[7]