Rain"bow` (-bō`), n. [AS. regenboga, akin to G.
regenbogen. See Rain, and Bow anything bent.]
A bow or arch
exhibiting, in concentric
bands, the several colors of the spectrum, and formed in the
part of the
hemisphere opposite
to the sun by the refraction and reflection of the sun's rays in drops of falling rain.
&fist; Besides the ordinary bow, called also primary rainbow, which is formed by two
refractions and one reflection, there is also another often seen exterior to it, called the
secondary rainbow, concentric
with the first, and separated from it by a small interval. It is formed by
two refractions and two reflections, is much fainter than the primary bow, and has its colors arranged in the reverse order from those of the
latter.
Lunar rainbow, a fainter arch or rainbow, formed by the moon. -- Marine rainbow, or Sea bow, a similar bow
seen in the
spray of waves at sea. -- Rainbow trout
(Zoöl.), a bright-colored trout (Salmo irideus), native of the
mountains of California, but now extensively introduced
into the Eastern States, Japan, and other countries; -- called also brook trout, mountain trout, and golden trout. -- Rainbow wrasse.
(Zoöl.) See under Wrasse. --
Supernumerary rainbow, a smaller bow, usually of red and green
colors only, sometimes seen within the primary or without the secondary rainbow, and in contact with them.
Hear it pronounced