Holy Week is the week which precedes the great festival of the Resurrection on Easter Sunday, and which consequently is used to commemorate the Passion of Christ, and the event which immediately led up to it. In Latin is it called hebdomada major, or, less commonly, hebdomada sancta, styling it he hagia kai megale ebdomas. Similarly, in most modern languages (except for the German word Charwoche, which seems to mean "the week of lamentation") the interval between Palm Sunday and Easter Day is known par excellence as Holy Week.
(Catholic Encyclopedia New Advent)