High-risk describes something that could easily go badly — injury, death, losing money, a plan failing. Doctors talk about high-risk patients (people more likely to get very sick). Banks talk about high-risk loans. The police talk about high-risk situations. It usually sits before a noun. High here means “a lot of,” not tall. It is calm, slightly formal English, common in news, medicine, and business. The pair is low-risk. Calling a person high-risk can sound cold, as if they were a number in a report, so careful speakers often soften it. It names the chance of harm, not how famous or how expensive something is.