The Collaborative International Dictionary of English v.0.48:

Cancroid \Can"croid\, a. [Cancer + oid.]
   1. (Zool.) Resembling a crab; pertaining to the Cancroidea,
      one of the families of crabs, including the genus
      Cancer.
      [1913 Webster]

   2. Like a cancer; as, a cancroid tumor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

cancroid
    adj 1: of or relating to a cancroid
    n 1: the most common form of skin cancer [syn: cancroid,
         squamous cell carcinoma]