Mid 17th century; earliest use found in Richard Saunders. From post-classical Latin peiorat-, past participial stem of peiorare to make worse (late 2nd or early 3rd cent. a.d.) from classical Latin pēior worse (functioning as the comparative of malus bad: see mal-) from the same Indo-European base as foot; compare -ior. Compare Middle French pejorer, Italian peggiorare, both in sense ‘to become worse’, Spanish †peorar, Portuguese piorar, Italian peggiorare, all in sense ‘to make (something) worse’. Compare earlier meliorate.