What is the meaning of Barrel_roll?

An aerobatic flying maneuver in which the pilot causes the airplane to complete one loop in the same time that the airplane completes one roll, creating the appearance that the airplane is riding on the inside of a cylinder.

A movement (usually during a car crash) where a car flips on its roof, then falls back on its wheels after doing at least one full 360° horizontal rotation.

To perform a barrel roll.

Source: wiktionary.org