'chigger' definitions:

Definition of 'chigger'

noun

Small tropical flea; the fertile female burrows under the skin of the host including humans [syn: chigoe, chigger, chigoe flea, Tunga penetrans]

noun

Larval mite that sucks the blood of vertebrates including human beings causing intense irritation [syn: harvest mite, chigger, jigger, redbug]

From: GCIDE

Jigger \Jig"ger\ (j[i^]g"g[~e]r), n. [A corrupt. of chigre.]
1. (Zool.) A species of flea (Tunga penetrans, or Sarcopsylla penetrans, or Pulex penetrans), which burrows beneath the skin; called also jigger flea. See Chigoe. [1913 Webster]
2. (Zool.) 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. [Southern U. S.] [Webster 1913 Suppl. +PJC]

From: GCIDE

Chigoe \Chig"oe\, Chigre \Chig"re\, n. [Cf. F. chigue, perh. fr. Catalan chic small, Sp. chico; or of Peruvian origin.] (Zool.) A species of flea (Tunga penetrans, formerly {Pulex penetrans}), common in the West Indies and South America, which often attacks the feet or any exposed part of the human body, and burrowing beneath the skin produces great irritation. When the female is allowed to remain and breed, troublesome sores result, which are sometimes dangerous. See Jigger. [Written also chegre, chegoe, chique, chigger, jigger.] [1913 Webster]
Note: The name is sometimes erroneously given to certain mites or ticks having similar habits. [1913 Webster]

From: GCIDE

chigger \chigger\ n.
1. a small tropical flea (Tunga penetrans, formerly {Pulex penetrans}); same as chigoe. [Also spelled chigre.]
Syn: chigoe, chigoe flea, Tunga penetrans. [WordNet 1.5]
2. a larval mite of the family Trombiculidae that sucks the blood of vertebrates including human beings, causing intense irritation, and serving to transmit several infectious diseases.
Syn: harvest mite, jigger, redbug. [WordNet 1.5]