Maundy Thursday is the Thursday before Easter Sunday.
Maundy Thursday in British English
noun
Christianity
the Thursday before Easter observed as a commemoration of the Last Supper
Maundy Thursday in American English
(ˈmɔndi)
the Thursday before Easter
Word origin
ME maunde, ceremony of washing the feet of the poor < OFr mandé < LL(Ec) mandatum, commandment of God < L (see mandate): from use of mandatum at the beginning of the prayer for washing the feet, commemorating Jesus' washingof the disciples' feet: see John 13:5, 34