xung phong

Etymology
.

The original meaning is "to charge ahead to assault", which probably developed into "to willingly throw oneself out of safety", then to current "to volunteer". Even now when its usage has spread widely outside of military contexts, the term still carries a slight militaristic tone.

Verb

 * 1)  to charge ahead to assault
 * 2) to volunteer for a task or mission
 * 1) to volunteer for a task or mission