A poem in triplets, in which the second or middle line rhymes with the first and third lines of the succeeding triplets. In the beginning of the poem lines 1 and 3 rhyme independently, and the poem must end with the first line of a new triplet. Dante's Divine Comedy is in this metre, and Byron has adopted it in The Prophecy of Dante. The scheme is as follows. -
x2a feel (a new rhyme for 1b and 3b).
x2b cries (a new rhyme for 1c and 4c).
2c place—(a new rhyme for 1d and 3d)
x2d ( a new rhyme for 1e and 3e)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894