Here is an excerpt from an article on the website www.anglicancompass by Greg Goebel.

I don’t think there has ever been a child who didn’t think I was saying Monday Thursday during the Holy Week announcements. Growing up, I thought today was Monday Thursday until about age 14. And when I finally learned it was “Maundy,” no one could explain why it was called that!

But friends, I have trekked through the boring dictionaries of liturgy for you! ‘Maundy’ is derived from the latin ‘mandatum’ which means basically “commandment.”

Because Thursday night of Holy Week corresponds to the Last Supper, it includes Jesus saying, “A new commandment I give to you, that you love one another as I have loved you.” This is the night of that New Commandment, in other words, it is New Commandment Thursday.

Maundy Thursday services traditionally include a focus on the Last Supper, not only as the beginning of the Triduum (the Great Three Days), but also as the institution of the Lord’s Supper, Eucharist, Communion. In many places, a foot washing service is included, and the service often ends with the Stripping of the Altar.