a bow or arc of prismatic colors appearing in the heavens opposite the sun and caused by the refraction and reflection of the sun's rays in drops of rain. Compare primary rainbow , secondary rainbow .

a similar bow of colors, esp. one appearing in the spray of a waterfall or fountain.

any brightly multicolored arrangement or display.

a wide variety or range; gamut.

a visionary goal

He pursued the rainbow of a singing career for years before becoming a success.

rainbow trout.

made up of diverse races, ethnic groups, etc.

a rainbow coalition of supporters.

noun

arc , band of color , bow , crescent , curve , prism , variegation , bubble , castle in the air , chimera , dream , fantasy , pipe dream , assortment , band , illusion , iris , spectrum