from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. To endure a punishment or consequence with dignity or stoicism.
- v. To accept a negative aspect of a situation in order to continue moving forward.
Possibly from the reported practice of soldiers biting a bullet to avoid crying out in pain, usually during a medical procedure or punishment. (While this is given frequently as an etymology, this source suggests that the term derives instead from the practice of biting open paper cartridges.) (Wiktionary)