Meaning

noun a book published annually by the graduating class of a high school or college usually containing photographs of faculty and graduating students

noun a reference book that is published regularly once every year

originFrom year + book. Compare Saterland Frisian Jierbouk (“yearbook”), West Frisian jierboek (“yearbook”), Dutch jaarboek (“yearbook”), German Low German Johrbook (“yearbook”), German Jahrbuch (“yearbook”), Swedish årsbok (“yearbook”), Faroese árbók (“annal, record, yearbook”).

Etymology from Wiktionary, CC BY-SA 3.0