the study of the history and significance of the feasts and seasons in the ecclesiastical calendar.

Origin of heortology

1900–05; < Greek heort(ḗ) a feast, festival + -o- + -logy
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Word Origin and History for heortology

"study of religious feasts and calendars," 1900, from Greek heorte "feast" + -ology. The immediate source of the English word is in French or German.

Online Etymology Dictionary, © 2010 Douglas Harper