Alexandrine introduce phrasal accentuation, or rigorously observe the medial caesura, as in French." Common usage within the literatures of European languages is broader still, embracing lines syllabic, accentual-syllabic, and (inevitably) stationed ambivalently between the two; lines of 12, 13, or even 14 syllables; lines with obligatory, predominant, and optional caesurae. Although alexandrines occurred in French verse as early as the 12th century, they were slightly looser rhythmically, and vied with the "décasyllabe" and "octosyllabe" for cultural prominence and use in various genres. "The alexandrine came into its own in the middle of the sixteenth century with the poets of the Pléiade
Tribrach (poetry) Oxford English Dictionary under 'Poetry Terms' lacks a formal definition, but does appear, primarily as a musical form, in some American dictionaries, such as Virginia Tech Multimedia Music Dictionary. Its appearance in English poetry is rare, as it tends to resolve into two disyllabic feet, depending upon the feet that surround it. Tribrach (poetry) A tribrach is a metrical foot used in formal poetry and Greek and Latin verse. In quantitative meter (such as the meter of classical verse), it consists of three short syllables; in accentual-syllabic verse (such as formal English verse), the tribrach consists of three unstressed syllables.