0 an arch (= curved shape) of different colours seen in the sky when rain is falling and the sun is shining:
1 an arch of many colors sometimes seen in the sky for a short time when it rains and the sun is shining
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!
Note that if a pair of vertices is joined by two rainbow paths then they have the same length.
Neither rainbows nor shadows have bodies, yet both are clearly visible.
While this feature renders rainbows and shadows corporeal, many other clearly perceptible items remain unextended, and so fall into the incorporeal class.
