A reproof is a negative comment, reprimand, or rebuke. Even the nicest kindergarten teacher in the world will give his students a reproof if they won't stop laughing and running around the classroom.
An athlete's bad behavior on or off the field might result in a reproof by his coach. and a long-distance bus driver will offer at least a mild reproof if a passenger is continuously talking loudly into her cell phone. Kids with strict parents receive more reproofs than those who have fewer rules to follow. Reproof comes from the Late Latin reprobāre, which means "disapprove, reject, or condemn."