Maundy vs ceremonial occasion

Maundy and ceremonial occasion both are nouns.

Word	Noun	Adjective	Verb	Adverb
Maundy	Yes	No	No	No
ceremonial occasion	Yes	No	No	No

As nouns, ceremonial occasion is a hypernym of Maundy; that is, ceremonial occasion is a word with a broader meaning than Maundy:

Maundy: a public ceremony on Maundy Thursday when the monarch distributes Maundy money
ceremonial occasion: a formal event performed on a special occasion

Other hypernyms of Maundy include ceremonial, ceremony, observance.

Maundy (noun)	ceremonial occasion (noun)
a public ceremony on Maundy Thursday when the monarch distributes Maundy money	a formal event performed on a special occasion