declension

Declension came into English (via Middle French) in the first half of the 15th century, originating in the Latin verb declinare, meaning "to inflect" or "to turn aside." The word seems to have whiled away its time in the narrow field of grammar until Shakespeare put a new sense of the word in his play Richard III in 1593: "A beauty-waning and distressed widow / … Seduc'd the pitch and height of his degree / To base declension and loath'd bigamy." This "deterioration" sense led within a few decades to the newest sense of the word still in common use, "descent" or "slope." The 19th century saw still another new sense of the word—meaning "a courteous refusal"—but that sense has remained quite rare.