A cravat is an old-fashioned, scarf-like necktie. If you come across some 18th-century portraits of wealthy men, you'll definitely see a few cravats.
You can think of the cravat as the ancestor of the tie that's often worn with a formal suit today. A cravat is basically a short scarf worn around the neck and tucked into the collar of a shirt. The word cravat comes from the French Cravate, "Croat" or "Croatian." And it was Croatian soldiers who first started the cravat craze in France during the 1630s. Croatia still observes a national Cravat Day every year on October 18th.