Noun

1. A barbaric act.

   These barbarisms can not be allowed to continue, they must be crushed or civilization will collapse.

2. The condition of existing barbarically.
   • 1879, William Tecumseh Sherman, Address to the Michigan Military Academy

     War is at best barbarism...It's glory is all moonshine.

3. An error in language use within a single word, such as a mispronunciation.
   • 2002, Hyman, Bad Grammar in Context, New England Classical Journal, 29, p. 94-101

     In the jargon of the ancient grammarian, penacilin would be a barbarism.