Hilarymas
noun
Hil·a·ry·mas
ˈhil(ə)rēməs
plural -es
: the feast of St. Hilary on January 13 in the Anglican calendar and January 14 in the Roman Catholic calendar
Word History
Etymology
Middle English Hillarimesse, from St. Hilary †ab a.d. 367 bishop of Poitiers + Middle English messe mass