Emily Dickinson Lexicon

PEARL, n. [perl; Fr. perle. It. and Sp. perla; Ir. pearla; Sax. pearl; Sw. pärla; D. paarl; G. perle; W. perlyn. This may be radically the same word as beryl, and so named from its clearness.]

1. A white, hard, smooth, shining body, usually roundish, found in a testaceous fish of the oyster kind. The pearl shell is called matrix perlarum, mother of pearl, and the pearl is found only in the softer part of the animal. It is found in the Persian seas and in many parts of the ocean which washes the shores of Arabia and the continent and isles of Asia, and is taken by divers. Pearls are of different sizes and colors; the larger ones approach to the figure of a pear; some have been found more than an inch in length. They are valued according to their size, their roundness, and their luster or purity, which appears in a silvery brightness. – Cyc. Nicholson. Encyc.
2. Poetically, something round and clear, as a drop of water or dew. – Drayton.
3. A white speck or film growing on the eye. – Ainsworth.