the Thursday of Holy Week, commemorating Jesus' Last Supper and His washing of the disciples' feet upon that day.
Origin of Maundy Thursday
late Middle English word dating back to 1400–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for maundy thursday
Christianity the Thursday before Easter observed as a commemoration of the Last Supper
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012