A quintain (Sicilian) poem is one written in five lines or one that uses five-line stanzas throughout the piece. In most cases, there are no rules regarding meter or line length. Usually, quintains are written in a specific rhyme sequence that stays consistent throughout the poem.
Different styles of quintains will require that the last word of one line rhymes with the last word of another specific line. For example, when a limerick style quintain is being used the last word of the first line must rhyme with the ending of the second line. The third line must end with a word that rhymes with the last word on the fourth line. Then, the fifth line must end with a word that rhymes with the endings on the first and second lines.
Different rhyming patterns get used depending on what type of quintain is being written. In the Sicilian style quintain, sometimes an iambic pentameter gets used. Sicilian quintains are identified by being written in a specific five-line rhyming sequence. The Sicilian style rhymes the end of the first line with the last words in the third and fifth lines. The last word of the second line rhymes with the ending of the fourth line giving this style of poem a unique rhythm.