Emily Dickinson Lexicon

BULL'S'EYE, n. [bull and eye.]

1. Among seamen, a piece of wood in the form of a ring, answering the purpose of a thimble. – Mar. Dict.
2. Aldebaran, a star of the first magnitude in the constellation Taurus. – Ash.
3. A small obscure cloud, ruddy in the middle, portending a great storm. – Encyc.
4. In architecture, a small circular or elliptical window.