bull's-eye

or bull's eye (bo͝olzˈīˌ)

1. a. The small central circle on a target.
   b. A shot that hits this circle.
2. a. A direct hit: scored a bull's-eye on the window with a snowball.
   b. The precise accomplishment of a goal or purpose: “With his overflowing style, [he] almost always hits the bull's-eye of universality” (William Zimmer).
3. A thick, circular piece of glass set, as in a roof or ship's deck, to admit light.
4. A circular opening or window.
5. a. A planoconvex lens used to concentrate light.
   b. A lantern or lamp having such a lens.
6. A piece of round hard candy.