0 a tool with sharp points used for breaking up and removing unwanted grass or plants that are covering the surface of a lawn (= an area of grass):
A scarifier attachment is mounted behind the vehicle.
The scarifier is for use with an asphalt concrete roadway refinisher.
Scarify the lawn vigorously by raking in two directions with a rake or scarifier.
A scarifier removes excess material and allows your grass room to breathe.