Source : Webster's Revised Unabridged Dictionary (1913)

Dys- \Dys-\
   An inseparable prefix, fr. the Greek ? hard, ill, and
   signifying ill, bad, hard, difficult, and the like; cf. the
   prefixes, Skr. dus-, Goth. tuz-, OHG. zur-, G. zer-, AS. to-,
   Icel. tor-, Ir. do-.