A species of flea (Tunga penetrans, or Sarcopsylla penetrans, or Pulex penetrans), which burrows beneath the skin; called also jigger flea. See Chigoe.
Any one of several species of small red mites (esp. Tetranychus irritans and Tetranychus Americanus) of the family Trombiculidae, which, in the larval or leptus stage, burrow beneath the skin of man and various animals, causing great annoyance. Also called chigger.