fuddy-duddy /ˈfʌdiˌdʌdi/adjective 1noun 1forms 3 adjective1 •(informal) Old-fashioned and persnickety or ineffective. noun1 •(informal) An old-fashioned, persnickety or ineffective person.My grandma is a fuddy-duddy when it comes to keeping her house clean. formsfuddy-duddies · fuddy-duddier · fuddy-duddiest