The Collaborative International Dictionary of English v.0.48:

Chancroid \Chan"croid\, n. [Chancre + -oil.] (Med.)
   A venereal sore, resembling a chancre in its seat and some
   external characters, but differing from it in being the
   starting point of a purely local process and never of a
   systemic disease; -- called also soft chancre.
   [1913 Webster]

WordNet (r) 3.0 (2006):

chancroid
    n 1: infectious venereal ulcer