Septuagesima
noun
Sep·tu·a·ge·si·ma ˌsep-tə-wə-ˈje-sə-mə 
-ˈjā-zə-
: the third Sunday before Lent
Word History
Etymology
Middle English, from Late Latin, from Latin, feminine of septuagesimus seventieth, from septuaginta seventy; from its being approximately seventy days before Easter
First Known Use
before the 12th century, in the meaning defined above