Verb (5-dan, む, intransitive)
1.  to grow wild;  to run to waste;  to become degenerate
2.  to become rough (of art, craft, etc.);  to lose refinement;  to deteriorate (of skill)
Auxiliary verb (5-dan, む)
3.  to intensify (of wind, rain, etc.);  to become more severe
usu. after -masu stem