A rainbow is an arch of different colours that you can sometimes see in the sky when it is raining.
Oh look, a rainbow!
...silk brocade of every colour of the rainbow.
2. countable noun [usually NOUNof noun]
A rainbow of colours is a wide range of bright colours.
...a rainbow of coloured cushions.
3.
See the end of the rainbow
rainbow in British English
(ˈreɪnˌbəʊ)
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.
a.
any similar display of bright colours
b.
(as modifier)
a rainbow pattern
3.
an illusory hope
to chase rainbows
4. (modifier)
of or relating to a political grouping together by several minorities, esp of different races
the rainbow coalition
Rainbow in British English
(ˈreɪnˌbəʊ)
noun
a member of the Rainbow Guides, the youngest group of girls (aged 5-7 years) in The Guide Association
rainbow in American English
(ˈreɪnˌboʊ)
noun
1.
an arc or ring containing the colors of the spectrum in consecutive bands, formed in the sky by the refraction, reflection, and dispersion of light in rain or fog
2.
a multicolored array or assortment
3.
a wide range or selection
adjective
4.
of many colors
5.
a.
of or involving the collaboration of members of diverse groups, esp. racial or minority groups
a rainbow commission to study housing
b.
designating a political coalition of diverse racial or minority groups