Six separate nouns are recorded with thius spellling in OED'. One is an item of clothing worn by bishops in the nineteenth century, and fashionable rich men in the early twentiewth century. This was a kind of waterproof protection to the upper foot and ankle. It is similar to, but smaller than, a gaiter.
One other meaning is worth mention. In US English, originally informal or slang, a spat was a quarrel or argument.