Source : Webster's Revised Unabridged Dictionary (1913)

Pigtail \Pig"tail`\, n.
   1. The tail of a pig.

   2. (Hair Dressing) A cue, or queue. --J. & H. Smith.

   3. A kind of twisted chewing tobacco.

            The tobacco he usually cheweth, called pigtail.
                                                  --Swift.

Source : WordNet®

pigtail
     n : a braid of hair on either side of the face