Quinquagesima \Quin`qua*ges"i*ma\, a. [L., fr. quinquagesimus the fiftieth, akin to quinquaginta fifty, quinque five. See Five.]

Fiftieth.

Quinquagesima Sunday, the Sunday which is the fiftieth day before Easter, both days being included in the reckoning; -- called also Shrove Sunday.

Source: Webster's Revised Unabridged Dictionary (1913)