When something serrates, it has a notched or saw-toothed edge.
Serrates can be sharp and can be used for cutting or gripping things.
Examples:
The knife serrates the bread when you cut it.
The saw serrates the wood when you use it.
She uses the scissors to serrate the paper.
The cat's tongue serrates the yarn when it licks it.
The shark's teeth serrate the fish when it bites it.
The dinosaur's teeth serrate the leaves when it eats them.