Source : Webster's Revised Unabridged Dictionary (1913)

Challis \Chal"lis\, n. [F. chaly, challis, a stuff made of
   goat's hair.]
   A soft and delicate woolen, or woolen and silk, fabric, for
   ladies' dresses. [Written also {chally}.]

Source : WordNet®

challis
     n : a soft lightweight fabric (usually printed)