n. 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: “Most marketing these days .... hits the bull's-eye for laughs, razzle-dazzle, and cleverness” (Jay Conrad Levinson).
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 plano-convex lens used to concentrate light.
b. A lantern or lamp having such a lens.
6. A piece of round hard candy.