octosyllabic

octosyllabic [ok‐toh‐sĭ‐lab‐ik], having eight syllables to the line. Octosyllabic verse in English is usually written in the form of iambic ortrochaic tetrameters. It appears in various forms including the In Memoriam stanza, but is most commonly found in couplets, both in light Hudibrastic verse and in more serious works such as Wordsworth's poem beginning

She was a phantom of delight
When first she gleamed upon my sight

In medieval French poetry, octosyllabic couplets were used in lais, fabliaux, and other kinds of poem.