Main Entry: con·cus·sion

Pronunciation: \kən-ˈkəsh-ən\

Function: noun

1 : a hard blow or collision
2 : a condition resulting from the stunning, damaging, or shattering effects of a hard blow ; especially : a jarring injury of the brain resulting in disturbance of cerebral function and sometimes marked by permanent damage

—con·cus·sive \-ˈkəs-iv\ adjective