an arch of colours visible in the sky, caused by the refraction and dispersion of the sun’s light by rain or other water droplets in the atmosphere. The colours of the rainbow are generally said to be red, orange, yellow, green, blue, indigo, and violet:all the colours of the rainbow
a display of the colours of the spectrum produced by dispersion of light.
a wide range of related and typically colourful things:a rainbow of medals decorated his chest
[as modifier] many-coloured:a big rainbow packet of felt pens
Phrases
at the end of the rainbow
used to refer to something much sought after but impossible to attain:the long-lost loving parent who waits at the end of every unhappy child’s rainbow
[with allusion to the story of a crock of gold supposedly to be found by anyone reaching the end of a rainbow]
chase rainbows (or a rainbow)
pursue an illusory goal:I couldn’t afford to waste petrol chasing rainbows as far as Leeds and back
