To doff means to take off or remove a piece of clothing, especially a hat. When a gentleman in an old movie tips his hat to greet someone, he's doffing it. Knights in medieval times would doff their helmets as a sign of respect or trust when entering a friend's castle.

While people rarely use doff in everyday conversation anymore, you'll encounter it in historical novels and older stories. Charles Dickens loved using it, and you might read about a character doffing his cap to show respect or doffing a coat after coming in from the cold.

The opposite of doff is don, which means to put on. So a firefighter might don protective gear before rushing into a burning building, then doff it afterward. Today, most people just say “take off” instead of doff, but the word survives in formal writing and period stories where it adds historical flavor.