Glossary of Poetic Terms

A poetic line that unfolds in three descending or “stepped” parts. Invented by William Carlos Williams who used the device in poems such as “Desert Music,” “The Descent,” and “Asphodel, That Greeny Flower,” the triadic line was taken up by poets such as Thom Gunn and Charles Tomlinson. Williams linked the triadic line to his concept of the “variable foot,” a metrical device he believed solved the tension of form in free verse. Variously interpreted, the variable foot has been taken to mean a unit of time, stress, syntax, rhythm, and typography.