The heptameter is usually divided into a tetrameter and a trimeter; the octameter, into two tetrameters.
The trimeter iambic is a foot longer than our heroic measure.
A trimeter is a division of verse consisting of three measures of two feet each.
The common-meter stanza contains four iambic lines, the first and third being tetrameter, and the second and fourth trimeter.
trimeter, trim′e-tėr, n. a division of a verse consisting of three measures.
A stanza made up of tetrameter alternating with trimeter is very common.
The Alexandrine of twelve syllables might seem to be the trimeter iambic of the ancients.
It is doubtful whether even the great Tragic poets could have made the trimeter tolerable as the vehicle of a long story.