Definition of "holy day of obligation" [holy day of obligation]
Roman Catholic Church A feast on which the faithful are obliged to hear Mass and abstain from servile work.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.