in Physiology, the rainbow. The word is Greek, ἰρις, supposed by some to be derived from ἵπτομαι, "I speak, I tell;" as being a meteor that is supposed to foretell, or rather to declare rain. See Rainbow.

Lunar Iris, or Moon-rainbow. See Rainbow, Lunar.

in Anatomy, a striped variegated circle round the pupil of the eye, formed of a duplicature of the uvea. See Anatomy Index.

IRIS is also applied to those changeable colours which sometimes appear in the glasses of telescopes, microscopes, &c. so called from their similitude to a rainbow. The same appellation is also given to that coloured spectrum, which a triangular prismatic glass will project on a wall, when placed at a due angle in the sun-beams.

the Flower de Luce, or Flag-flower, &c. a genus of plants, belonging to the triandra class, and in the natural method ranking under the sixth order, Emotor. See Botany Index.