Wordology, Whet One’s Appetite

This means to arouse interest in something, usually food. The whet in 'whet one’s appetite' refers to a sharpening, as in sharpening one’s interest in something. Someone may whet your appetite by providing a small taste, an example or enticing description that makes you want more of the item in question or to know more about a subject. Whet one’s appetite dates back to the early 1600s to describe stimulating an appetite for food. Whet is a verb, to sharpen, as on a whetstone, or to make more aware.