Other forms: erred, erring, errs
To err is to make a mistake. Err on the side of caution, to err is human, he erred badly.
It survives almost entirely in two phrases: to err is human, from Pope, and err on the side of, meaning to choose the safer mistake deliberately. Both pronunciations are used, rhyming with her or with air, and neither is wrong.
1verberrTo make a mistake.
“Even the best doctors can err, so it's wise to get a second opinion.”
err is a mistaking.
Latin errare means to wander or stray. Error, erratic and errand all come from wandering.
Proto-Indo-European
*h₁ers- — to be angry, lose one's temper
Latin
errō — wander, stray, err, mistake
Old French
errer — to wander, err, mistake
Middle English
erren
English, today
err
From Middle English erren, from Old French errer (“to wander, err, mistake”), from Latin errō (“wander, stray, err, mistake”), from Proto-Indo-European h₁ers- (“to be angry, lose one's temper”). Cognate with Old English eorre, ierre (“anger, wrath, ire”), Old English iersian (“to be angry with, rage, irritate, provoke”), Old English ierre (“wandering, gone astray, confused”).
Etymology from Wiktionary, CC BY-SA