err (third-person singular simple present errs, present participle erring, simple past and past participle erred) (intransitive, formal) To make a mistake. He erred in his calculations, and made many mistakes.

Definition of err verb from the Oxford Advanced Learner's Dictionary to make a mistake To err is human… Word Origin Middle English (in the sense ‘wander, go astray’): from Old French errer, from Latin errare ‘to stray’. Want to learn more?