A tribrach is a metrical foot consisting of three short syllables. In quantitative verse, this means three short syllables. In accentual-syllabic verse, this means three unstressed syllables.
The tribrach is relatively rare as a consistent foot in extended poetic compositions. Its use is more common as a substitute foot within a larger metrical scheme, often to introduce a sense of speed or variation. The substitution creates a rhythmic effect that can draw attention to specific words or phrases.
While theoretically possible in many metrical systems, the practical application of a tribrach depends on the specific language and its prosodic characteristics. In English poetry, its occurrence is often debated due to the inherent difficulty in consistently achieving three consecutive unstressed syllables.