Septuagesima

from WordNet (r) 3.0 (2006)

Septuagesima
    n 1: the 3rd Sunday before Lent (or the 9th before Easter) [syn:
         {Septuagesima}, {Septuagesima Sunday}]

from The Collaborative International Dictionary of English v.0.48

Septuagesima \Sep`tu*a*ges"i*ma\, n. [NL., fr. L. septuagesimus
   the seventieth, fr. septuaginta seventy.] (Eccl.)
   The third Sunday before Lent; -- so called because it is
   about seventy days before Easter.
   [1913 Webster]