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' washing of the disciples' feet: see John 13:5, 34
See Maundy Thursday in American Heritage Dictionary 4
Origin: From Middle English maunde, ceremony of washing the feet of the poor on this day
Origin: , from Old French mande
Origin: , from Latin (novum) mandātum, (new) commandment (from Jesus's words to the Apostles after washing their feet, John 13:34); see mandate.