daffyEnglishOxford Dictionary of Englishdaffy /ˈdafi / ▸ adjective ( daffier, daffiest) informal mildly eccentric or strange: he spent the entire movie playing this daffy, affable old professor there are plenty of daffy ideas together with the brilliant ones. – DERIVATIVES daffiness noun daffily adverb– ORIGIN late 19th century: from northern English dialect daff ‘simpleton’ + -y1; perhaps related to daft.