rainbow

noun

1. a bow or arc of prismatic colors appearing in the heavens opposite the sun and caused by the refraction and reflection of the sun’s rays in drops of rain.Compare primary rainbow, secondary rainbow.
2. a similar bow of colors, especially one appearing in the spray of a waterfall or fountain.
3. any brightly multicolored arrangement or display.
4. a wide variety or range; gamut.
5. a visionary goal: He pursued the rainbow of a singing career for years before becoming a success.
6. rainbow trout.

adjective

7. having a diverse membership; including representatives from multiple racial and ethnic groups: a rainbow coalition of minority groups.

noun

1. a bow-shaped display in the sky of the colours of the spectrum, caused by the refraction and reflection of the sun’s rays through rain or mist
2. 1. any similar display of bright colours
   2. (as modifier)a rainbow pattern
3. an illusory hopeto chase rainbows
4. (modifier) of or relating to a political grouping together by several minorities, esp of different racesthe rainbow coalition

noun

1. a member of the Rainbow Guides, the youngest group of girls (aged 5-7 years) in The Guide Association

n.

Old English renboga; see rain (n.) + bow (n.). Common Germanic compound (cf. Old Frisian reinboga, Old Norse regnbogi, Swedish regenbåge, Dutch regenboog, German Regenbogen). Rainbow trout (1876, American English) so called for its resplendent colors. Old English also had scurboga “shower-bow.”

1. An arc-shaped spectrum of color seen in the sky opposite the Sun, especially after rain, caused by the refraction and reflection of sunlight by droplets of water suspended in the air. Secondary rainbows that are larger and paler sometimes appear within the primary arc with the colors reversed (red being inside). These result from two reflections and refractions of a light ray inside a droplet.

The colored arch in the sky that is often seen after a rain. The rainbow is formed when water droplets in the air cause the diffraction of sunlight.