err Definition

err
verb, intr erred, erring

1. To make a mistake, be wrong, or do wrong.

Thesaurus: mistake, slip up, misjudge, lapse, fail, blunder.
2. To sin.

Thesaurus: sin, trespass, offend, transgress, go astray, deviate.

Idiom: err on the side of something

To run the risk of (a particular fault) in order to avoid an opposite and greater fault.
Example: Err on the side of caution

Etymology: 14c: from Latin errare to stray.