Adam Jacot de Boinod runs the blog The Wonder of Whiffling (also the name of a book he’s written) that lists interesting, little known, and sometimes humorous words, often with their origins or historical context. Adam shared a few examples in a recent comment on this blog, showing the original meanings of commonly used words.
Grape – originally a hook for gathering fruit and later a cluster of fruit growing together.
Friend – a lover, later a relative or kinsman
Sky – meaning a cloud
Frantic – insane
Corset – a little body
Mortgage – a death pledge
In Tudor times, drink actually meant to smoke tobacco; walk – to roll, toss, move about, and later to press cloth; and steward – a keeper of the pigs and later, as wealth expanded, of herds of cattle and land.