roll bar

or roll·bar


noun

a heavy steel transverse bar in the form of an inverted U rising from the framework of an automobile to prevent its occupants from being crushed if the vehicle rolls over.

Origin of roll bar

First recorded in 1950–55

British Dictionary definitions for rollbar

rollbar
/ (ˈrəʊlˌbɑː) /

noun

a bar that reinforces the frame of a car, esp one used for racing, rallying, etc, to protect the driver if the car should turn over