Laetare Sunday
Laetare Sunday (/liːˈtɛərɪ/ or /laɪˈtɑrɪ/ as in ecclesiastical Latin),[1] so called from the incipit of the Introit at Mass, "Laetare Jerusalem" ("O be joyful, Jerusalem"
(from Isaiah 66:10, masoretic text), is a name often used to denote the fourth Sunday of the season of Lent in the Christian liturgical calendar. This Sunday is also known as Mothering Sunday, Refreshment Sunday, Mid-Lent Sunday (in French mi-carême), and Rose Sunday (either because the golden rose sent by the popes to Catholic sovereigns used to be blessed at this time or because the use of rose-colored vestments instead of violet ones was permitted). The term "Laetare Sunday" is used predominantly, though not exclusively, by Roman Catholics and some Anglicans. The word translates from the Latin laetare, singular imperative of laetari to rejoice.
http://en.m.wikipedia.org/wiki/Laetare_Sunday