An anorak is a waterproof jacket with a hood, originally worn by people living in the Arctic. The Inuit and other northern peoples created these practical garments from animal skins to protect themselves from freezing winds, snow, and rain. Traditional anoraks had no front zipper: you pulled them over your head like a hoodie.

Today, anoraks are popular outdoor gear for hiking, camping, and rainy weather. Modern versions are usually made from synthetic materials that keep water out while letting your body breathe. Many anoraks have a large front pocket called a kangaroo pocket where you can warm your hands or stash small items.

In British English, anorak has developed a second, more playful meaning: it describes someone who is intensely interested in a particular hobby or topic, especially one that others might find boring or overly technical. If your friend memorizes every detail about trains or collects encyclopedic knowledge about a TV show, someone might affectionately call them an anorak.