Mother's Day

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The second Sunday in May, observed in the United States as a day honoring mothers.

from the GNU version of the Collaborative International Dictionary of English.

• A day appointed for the honor and uplift of motherhood by the loving remembrance of each person of his mother through the performance of some act of kindness, visit, tribute, or letter. The founder of the day is Anna Jarvis, of Philadelphia, who designated the second Sunday in May, or for schools the second Friday, as the time, and a white carnation as the badge.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A day in honor of mothers, which falls on the second Sunday in May in the United States, and on the fourth Sunday of Lent, exactly three weeks before Easter Sunday, in the United Kingdom and Ireland.

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

• noun second Sunday in May