If someone or something whets your appetite for a particular thing, they increase your desire to have it or know about it, especially by giving you an idea of what it is like.
例句
A really good catalogue can also whet customers' appetites for merchandise.一份真正好的商品目錄也可以激起顧客購買的欲望。...lectures he hopes might whet the appetite and keep students' enthusiasm.他希望能激發學生們的興趣，保持他們的熱情的講座