crashcrashcrashes1noun (pluralcrashes)1an accident when something that is moving hits another thing: He was killed in a car crash.a plane crash2a loud noise when something falls or hits another thing: I heard a crash as the tree fell.crashcrashcrashescrashedcrashing2verb (crashes, crashing, crashed)1to have an accident in a car or other vehicle and hit something: The bus crashed into a tree. I crashed my father's car.2to fall or hit something with a loud noise: The tree crashed to the ground.3If a computer crashes, it suddenly stops working.