hazard
Something that could cause harm, like a wet floor, a tree near a toboggan run, or a loose shoelace.
risk
The chance that a hazard causes harm, together with how bad the harm could be.
likelihood
How likely something is to happen.
severity
How serious the harm would be if it happened.
risk control
An action that lowers risk, like removing a hazard, changing the activity, wearing equipment or adding supervision.
concussion
A brain injury caused by a hit to the head, face, neck or body that makes the head move quickly.