Armistice Day ar·mis·ti·ceday uncommon noun 1. a legal holiday in the United States; formerly Armistice Day but called Veterans'' Day since 1954 SynonymsVeterans' DayArmistice DayNovember 11 Related words Broader terms legal holiday Parts November WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.