A tetrapody (also called tetrameter) contains four identical or regular feet, creating a common, balanced line length in English verse, as exemplified in iambic tetrameter or trochaic tetrameter. Tetrapody appears throughout English poetry from ballads to contemporary verse because its four-foot length balances musicality with complexity; it's flexible enough for varied emotional effects while remaining structured enough to be immediately recognizable, making it a reliable foundation for countless poetic traditions.

Tetrapody describes a metrical structure composed of four metrical feet per line (e.g., iambic tetrameter). It’s a common line length in English poetry (e.g., in ballads or hymns) and offers a balanced rhythm—long enough for development, short enough for memorability. Tetrapody contrasts with pentameter (five feet) and trimeter (three). Prosodists examine tetrapodic lines for regularity, substitutions, and how stanzaic forms (e.g., quatrains) interact with this line length.