Dibrach is a term used in poetry to describe a metrical foot consisting of two short syllables. There are several synonyms for this term depending on its use. One synonym is "pyrrhic," which comes from the Greek word "pyrrichios," meaning "fire-dance," and describes a foot made up of two unstressed syllables. Another synonym is "trochee," which is a foot consisting of a stressed syllable followed by an unstressed one. Lastly, "iamb" is another synonym for dibrach, which is a metrical foot made up of an unstressed syllable followed by a stressed one. These synonyms are important for studying poetry and understanding the rhythmic structure of a poem.