pentameter (adj.)youdaoicibaDictYouDict[pentameter 词源字典]
1540s, from Middle French pentametre, from Latin pentameter, from Greek pentametros (adj.) "having five measures," from pente "five" (see five) + metron "measure" (see meter (n.2)). As a noun from 1580s.[pentameter etymology, pentameter origin, 英语词源]