make one's bones

Verb

make one's bones (third-person singular simple present makes one's bones, present participle making one's bones, simple past and past participle made one's bones)

1. To commit a murder in order to be respected in a criminal gang.
   • 1976, Gloria Vitanza Basile, The Godson (page 232)

     Mario Cacciatore was fourteen when he made his bones.

2. (figuratively, by extension) To establish one's bona fides; to establish status and respect.