Other forms: mackintoshes
A mackintosh is a kind of raincoat. If you have to walk your dog in the pouring rain, you may want to wear a mackintosh.
You may think of a particular brand of computer or a piece of fruit when you see the word mackintosh, but those are spelled differently. Mackintosh is the name for a long, waterproof jacket, particularly in the U.K. The word is sometimes used for other waterproof items, like a mackintosh hat, and it's often abbreviated as mac. In 1823, a Scot named Charles Macintosh invented a waterproofing process, and the word (spelled both with and without a "k") stuck.