A pigtail is a section of hair tied at the back or sides of a person's head so that it sticks out a little or hangs down. Although pigs only have one, pigtails often come in pairs.
Some people think pigtails and braids are two different hairstyles (and often, a single pony tail to be a third), but others just call them all pigtails. The word, an American invention, originally described a twisted piece of chewing tobacco that was thought to resemble a pig's curly tail. The hairstyle was first called pigtails in the mid-1700s.