make (one’s) bones
v.— «They have reinstituted the requirement that before someone is made a soldier, he will have to ‘make his bones.’ That is, he will have to kill someone.» —“FBI Agent Nearly Was Inducted Into Mafia” by Larry Margasak AP Apr. 22, 1988. (source: Double-Tongued Dictionary)
Further reading
Is there such a thing as a “neutral” accent, and if so what does it sound like? And that quirk in the way southern Californians talk about freeways. They’ll say things like take the 405 and get on the 8. Why the definite article...
Floordrobe is the new word for an old habit: piling your clothes on the floor instead of putting them away. The Oxford English Dictionary recently added an entry for it, defining floordrobe as “an untidy heap of discarded clothing left on the floor...