ly·on·naise \ˈlīəˌnāz, ˌ ̷ ̷ ̷ ̷ˈ ̷ ̷\adjective Etymology: French (à la) lyonnaise in the manner of Lyons, from feminine of lyonnais of Lyons, from Lyon Lyons, France : prepared or seasoned with onions and sometimes parsley < lyonnaise potatoes > < potatoes lyonnaise >