Ill-treatment is the cruel behaviour itself — the noun for what happens when someone is cruel to a child, an animal, or anyone weaker. Doctors, social workers, and courts use it when they talk about harm that was done on purpose, often again and again, not one accident. It can mean hitting, starving, shutting someone in, or wearing a person down with words. Though actually, the short gloss you sometimes see, to be cruel, is the verb idea; this word names the cruelty as a thing you can report, prove, or stop. In daily chat, people often say abuse or cruelty instead. Ill-treatment still turns up in news headlines and official reports, and it keeps that same serious, slightly formal tone. It is not a casual complaint about a strict teacher or a tough sports coach.