Septuagesiman.

Etymology: Originally (i) < post-classical Latin septuagesima (see below). In later use reinforced by Old French (rare) septuagesme, Old French, Middle French septuagesime (compare Old French (rare) septuagisme ; French Septuagésime ) the period beginning with the third Sunday before Lent and ending with Shrove Tuesday (13th cent.; end of the 12th cent. as septuagisme ), the third Sunday before Lent (13th cent.) < post-classical Latin septuagesima the third Sunday before Lent (7th cent.), period of seventy days from the third Sunday before Lent to the Saturday in Easter week (frequently from 11th cent. in British sources), use as noun (short for dies septuagesima 70th day) of feminine of classical Latin septuāgēsimus seventieth < septuāgintā seventy (see Septuagint n.) + -ēsimus, extended form (after vīcēsimus) of -simus, suffix used to form ordinal numerals.Compare Old Occitan Septuagezima (14th cent. or earlier), Spanish Septuagésima (13th cent.), Italian settuagesima (c1300 as septuagesima ). In liturgical use in post-classical Latin after quinquagesima Quinquagesima n., but apparently only as an arithmetic approximation, since even using inclusive counting the period comprises 64 days, not the 70 which its name would suggest. The arithmetic inaccuracy was noted already in the 8th cent. by Alcuin, who considered interpreting the term as referring to the seventieth day before Low Sunday as a possible alternative explanation. Compare discussion at Sexagesima n. The Old English form Septuagessimam (see α. forms) is after the Latin accusative singular.