Something that's racy is zesty and exciting. The racy thriller you checked out of the library is so engrossing that you can't put it down, even at bedtime.
You can use the adjective racy for things that are robust or full of flavor, especially wine. It's also a good way to describe zesty, thrilling things, like racy movie plots, as well as things that are bawdy or verge on inappropriate, like the racy videos that are blocked on your school's computers. This word comes from an old meaning of race, "flavor."