What type of poetry is defined as lacking rhyme and regular meter?

Free verse poetry is characterized by its freedom from traditional constraints of rhyme and meter. This form allows poets to express their thoughts and emotions more fluidly and organically, without being bound by established patterns of sound and rhythm. By breaking away from these structures, free verse enables a diverse range of expression, accommodating a variety of subjects and styles.

In contrast, verse narrative typically adheres to a more structured form, often incorporating rhyme and rhythm to tell a story. Lyric poetry, while sometimes free in form, often possesses musical qualities and can involve rhyme and regular meter. A sestina is a specific poetic form that features a fixed pattern of words and structured repetition, which is distinct from the free-form qualities of free verse. This is why free verse is the correct answer, as it embodies the definition of lacking rhyme and a regular meter.