To rub or on with some substance, as a piece of stone, for the purpose of sharpening; to sharpen by attrition; as, to whet a knife.

That which whets or sharpens; esp., an appetizer.

sharpen by rubbing, as on a whetstone

To make sharp, keen, or eager; to excite; to stimulate; as, to whet the appetite or the courage.

make keen or more acute; "whet my appetite"

The act of whetting.