/ Dictionary / Index H holy day of obligation: Meaning and Definition of Find definitions for: ho'ly day" of obliga'tion Pronunciation: [key] a day on which Roman Catholics are duty-bound to attend Mass and abstain from certain kinds of work. a day on which Episcopalians are expected to take communion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. holy day Holy Family Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language