Source : Webster's Revised Unabridged Dictionary (1913)

Ichthyosis \Ich`thy*o"sis\, n. [NL., fr. Gr. ? fish.] (Med.)
   A disease in which the skin is thick, rough, and scaly; --
   called also {fishskin}. -- {Ich`thy*ot"ic}, a.

Source : WordNet®

ichthyosis
     n : any of several congenital diseases in which the skin is
         fishlike (dry and scaly)