golden wedding
From Longman Dictionary of Contemporary Englishgolden weddingˌgolden ˈwedding British English noun [countable] CELEBRATEthe date that is exactly 50 years after a wedding SYN golden anniversary, → diamond wedding, silver weddingExamples from the Corpusgolden wedding• Another successful choice would be a golden wedding anniversary.• The pair, both 73, decided to quit on the same day they celebrated their golden wedding.