literary artifice used in VERSIFICATION. It appears in Asian poetry but was almost unknown in Greece and Rome. When accentual meters replaced classical quantitative meters, rhyme developed, especially in Latin Christian poetry. In medieval vernacular verse, end rhyme (at a line end), assonance (repeated similar vowel sounds), and alliteration (repeated consonants, especially at word beginnings) were common. From 1300 until the 16th-cent. rise of blank verse (see PENTAMETER) rhyme was the outstanding verse device. Many modern poets use imperfect or approximate rhymes (e.g., groaned and ground). Single, or masculine, rhyme dominates in English, double, or feminine, rhyme in Spanish and Italian; German and French use both. Triple rhymes are uncommon in serious verse. Words spelled but not sounded alike are sometimes called eye rhymes. Set patterns of rhyme form such verse structures as the SONNET and heroic couplet.