Thursday before Easter, mid-15c., from Middle English maunde "the Last Supper," also "ceremony of washing the feet," from Old French mandé, from Latin mandatum "commandment" (see mandate); said to be so called in reference to the opening words of the church service for this day, Mandatum novum do vobis "A new commandment I give unto you" (John xiii:34), words supposedly spoken by Jesus to the Apostles after washing their feet at the Last Supper.