rainbownoun [ C ]uk /ˈreɪn.bəʊ/ us /-boʊ/
- Look over there - there's a rainbow!
- The glass prism refracted the white light into the colours of the rainbow.
- The colours of the spectrum - red, orange, yellow, green, blue, indigo and violet - can be seen in a rainbow.
- She did a stencil of a rainbow on her daughter's bedroom wall.
- There's a double rainbow!