The Collaborative International Dictionary of English v.0.48:

Morosis \Mo*ro"sis\ (m[-o]*r[=o]"s[i^]s), n. [NL., fr. Gr.
   mw`rwsis, fr. mw^ros silly, foolish.] (Med.)
   Idiocy; fatuity; stupidity.
   [1913 Webster]