a special anniversary of an event, especially one that took place 25, 50 or 60 years ago; the celebrations connected with it （尤指 25 周年或 50 周年的）周年纪念，周年大庆，周年庆祝 Word Originlate Middle English: from Old French jubile, from late Latin jubilaeus (annus) ‘(year) of jubilee’, based on Hebrew yōb̲ēl, originally ‘ram's-horn trumpet’, with which the jubilee year was proclaimed.