man up

verb4

1. •
   To be brave or tough enough to deal with something in a manner that is considered strong or manly. (Compare man (“brace oneself, steel oneself”))

   • I was wondering when he would man up and marry that girl he knocked up.
   • You need to man up and confront your boss about her behavior.
2. •
   To staff adequately; to staff up; to successfully fill all needed labor positions. (Compare man (“supply with staff”).)
3. •
   To vigorously guard the opponent to whom one is assigned.

   • They must be athletic enough to man up on a solid number two receiver and yet be physical enough to step into the line scrimmage and tackle a running back. — 2005
4. •
   (Of personnel) to assemble, each person manning (attending to) his station, prepared for the departure of an aircraft, ship, etc. (Compare man (“supply with staff; take up position to operate”).)