boutonniere
From Longman Dictionary of Contemporary Englishboutonnierebou‧ton‧ni‧ere /buːˌtɒniˈeə $ ˌbuːtnˈɪr/ noun [countable] American EnglishHBP a flower that a man wears fastened to his jacket at a wedding SYN buttonhole British EnglishOrigin boutonniere (1800-1900) French boutonnière, from bouton “button”