Late 16th century; earliest use found in William Webbe (fl.?1566–1591), author. From classical Latin penthēmimeris (in post-classical Latin also penthemimeres) metrical unit consisting of two and a half feet, caesura in the middle of the third foot (2nd cent. a.d.; 1st cent. a.d. as a Greek word) from Hellenistic Greek πενθημιμερές metrical unit consisting of two and a half feet, πενθημιμερής caesura in the middle of the third foot, uses as noun of neuter (short for πενθημιμερὲς μέτρον) and feminine (short for τομὴ πενθημιμερής) respectively of πενθημιμερής consisting of five halves from ancient Greek πέντε five + ἡμι- + -μερής.