IPA: //ˈskærɪfaɪər//
KK: /ˈskærɪfaɪər/
A tool used to break up and loosen the soil or vegetation on the surface of a lawn, often with spikes or prongs.
The gardener used a scarifier to prepare the lawn for new grass seed.
Scarifier → It is formed from "scar" (from Latin *scarificare*, meaning to make a small cut) and "-er" (meaning a person who). A scarifier is a person or tool that makes small cuts in the surface, often used in gardening or medical contexts.
Think of someone who makes 'small cuts' ('scar') — that's what a scarifier does.