Concussion
Etymology
From Latin “concussio,” from “concutere” (to shake violently) — “con-” (together) and “quatere” (to shake). The etymology captures the mechanism exactly: the harm comes not from the skull cracking but from the brain being shaken inside it. The same “shaking” root gives “percussion” and “discuss,” which once meant to shake something apart.
noun · /kuhn-KUSH-uhn/
A brain injury caused by a blow or jolt that makes the brain move inside the skull, temporarily disrupting how it works.
What it names
An injury long dismissed as “getting your bell rung” but now understood as real damage — invisible on ordinary scans, yet capable of lasting harm, especially if repeated.
Example
The coach pulled him off the field after the collision, knowing that playing on with a concussion risked far worse damage.
Related idea
A concussion is a trauma to the brain specifically; a fracture is a break in a bone. Both are injuries, but a fracture shows plainly on an X-ray while a concussion may leave no mark at all — which is exactly why it was underestimated for so long.