Source : Webster's Revised Unabridged Dictionary (1913)

Chigoe \Chig"oe\, Chigre \Chig"re\, n. [Cf. F. chigue, perh. fr.
   Catalan chic small, Sp. chico; or of Peruvian origin.]
   (Zo["o]l.)
   A species of flea ({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}.]

   Note: The name is sometimes erroneously given to certain
         mites or ticks having similar habits.

Source : WordNet®

chigger
     n 1: small tropical flea; the fertile female burrows under the
          skin of the host including humans [syn: {chigoe}, {chigoe
          flea}, {Tunga penetrans}]
     2: larval mite that sucks the blood of vertebrates including
        human beings causing intense irritation [syn: {harvest
        mite}, {jigger}, {redbug}]