senarius
noun
se·nar·i·us si-ˈner-ē-əs 
plural senarii si-ˈner-ē-ˌī
-ē-ˌē
: a verse consisting of six feet especially in Latin prosody
Word History
Etymology
Latin, from senarius consisting of six each, from seni six each, from sex six — more at six
First Known Use
1540, in the meaning defined above