1. A small circular or oval wooden block without sheaves, having a groove around it and a hole through it, used for connecting rigging.
2. A small round cloud, with a ruddy center, supposed by sailors to portend a storm.
3. A small thick disk of glass inserted in a deck, roof, floor, ships side, etc, to let in light.
4. A circular or oval opening for air or light.
5. A lantern, with a thick glass lens on one side for concentrating the light on any object; also, the lens itself.
6. (Science: astronomy) aldebaran, a bright star in the eye of taurus or the bull.
7. The center of a target.
8. A thick knob or protuberance left on glass by the end of the pipe through which it was blown.
9. A small and thick old-fashioned watch.