daffyEnglishOxford New American Dictionarydaffy /ˈdafē, ˈdæfi / ▸ adjective (daffier, daffiest) informal silly; mildly eccentric: daffy anecdotes. – DERIVATIVES daffiness ,daffily – ORIGIN late 19th century : from northern English dialect daff ‘simpleton’ + -y1; perhaps related to daft.