rain·bow (r?n?b??)n.1. a. An arc of spectral colors, usually identified as red, orange, yellow, green, blue, indigo, and violet, that appears in the sky opposite the sun as a result of the refractive dispersion of sunlight in drops of rain or mist.b. A similar arc or band, as one produced by a prism or by iridescence.c. A graded display of colors.2. An illusory hope: chasing the rainbow of overnight success.3. A diverse assortment or collection.[Middle English, from Old English r?nboga : r?n, rain + boga, bow; see bow3.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.rainbow (?re?n?b??) n1. (Physical Geography) 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 mist2. a. any similar display of bright coloursb. (as modifier): a rainbow pattern. 3. an illusory hope: to chase rainbows. 4. (Government, Politics & Diplomacy) (modifier) of or relating to a political grouping together by several minorities, esp of different races: the rainbow coalition. Rainbow (?re?n?b??) na member of the Rainbow Guides, the youngest group of girls (aged 5-7 years) in The Guide AssociationCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014rain?bow (?re?n?bo?) n. 1. a bow or arc of prismatic colors in the heavens opposite the sun; caused by the refraction and reflection of the sun’s rays in drops of rain. 2. a similar bow of colors, esp. one 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. adj. 6. of many colors; multicolored. 7. made up of diverse races, groups, etc.: a rainbow coalition. [before 1000] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.rain·bow (r?n?b??) 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.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.rainbow – Comes from Old Norse regnbogi (becoming Old English renboga, ren, “rain,” and boga, “bend, bow”) and is a bow or arch of the colors of the prism that is formed in the sky opposite to the sun by the reflection, double refraction, and dispersion of the sun’s rays in falling drops of rain.See also related terms for reflection.Farlex Trivia Dictionary. © 2012 Farlex, Inc. All rights reserved.Rainbow a rainbow as a symbol of a past storm.Examples: rainbow of hope, 1876; of the storms of life, 1813.Dictionary of Collective Nouns and Group Terms. Copyright 2008 The Gale Group, Inc. All rights reserved.