1. To be discharged from the United States military through an administrative procedure. One of my soldiers chaptered out after it was determined he was mentally unfit to serve.
2. To discharge someone from the United States military in this way. In this usage, a noun or pronoun is used between "chapter" and "out." They were going to chapter me out because of what happened, but they ended up giving me a second chance to serve my term of service.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.