Verb (5-dan, む, intransitive)
1.  to spring;  to bound;  to bounce
2.  to be stimulated;  to be encouraged;  to get lively
Verb (5-dan, む, transitive)
3.  to pay handsomely;  to splurge;  to part eagerly with (money, etc.)
Verb (5-dan, む, intransitive)
4.  to breathe hard;  to pant;  to be out of breath