Ash Wednesday

from The American Heritage® Dictionary of the English Language, 4th Edition

• n. The seventh Wednesday before Easter and the first day of Lent, on which many Christians receive a mark of ashes on the forehead as a token of penitence and mortality.

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A Christian day of penitence, the first day of Lent. It is a movable feast which takes place 40 days before Easter (excluding Sundays).

from the GNU version of the Collaborative International Dictionary of English

• The first day of Lent; -- so called from a custom in the Roman Catholic church of putting ashes, on that day, upon the foreheads of penitents.
• n. See in the Vocabulary.

from The Century Dictionary and Cyclopedia

• n. The first day of Lent.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• n. the 7th Wednesday before Easter; the first day of Lent; the day following Mardi Gras (`Fat Tuesday'); a day of fasting and repentance