Select the correct description for "trimeter" in a metrical context.

The term "trimeter" refers specifically to a line of poetry that contains three metrical feet. In poetry, a "foot" is a group of syllables that together comprise a unit of rhythm. When a line is classified as a trimeter, it means that the rhythmic structure is made up of three distinct feet, creating a specific pattern of stressed and unstressed syllables.

This definition is foundational for understanding various types of metrical verse. For example, lines in iambic trimeter would consist of three iambs, while a trochaic trimeter would consist of three trochees. Recognizing the structure of trimeter helps in analyzing the rhythm and overall flow of a poem. The other descriptions regarding different numbers of feet either overestimate or do not provide the correct number of feet associated with the term "trimeter," thus making the identification of three feet as the defining characteristic imperative.