Rainbow is an English word name taken directly from the colorful natural phenomenon.
Rainbow is an English word name whose meanings require no etymology — the natural phenomenon of light refracted through water droplets into a visible spectrum has been freighted with human significance since long before English existed. In the Hebrew Bible the rainbow is the sign of God's covenant with Noah after the flood, a promise that the world will not be destroyed again by water. In Norse mythology the Bifröst is a shimmering rainbow bridge connecting Midgard to Asgard.
In Andean cosmologies the rainbow (k'uychi in Quechua) is a powerful and sometimes dangerous spirit, and across Indigenous North American traditions it carries messenger and transformative associations. The name thus enters an extraordinarily old symbolic conversation the moment it is spoken. As a given name, Rainbow gained traction in countercultural communities of the 1960s and 1970s, part of a broader movement toward nature names and aspirational vocabulary names — Sunshine, River, Meadow, Leaf — that rejected the inherited European surname-and-saint framework.
It was used in intentional communities, by artists, and by parents who wanted to give a child a name that was literally a visible natural wonder. Rainbow Sun Francks, the Canadian actor, is among its more prominent contemporary bearers. In the twenty-first century Rainbow has taken on additional resonance as a symbol of LGBTQ+ pride and visibility, which means the name now layers a political and community identity onto its older natural and spiritual meanings. For some families this is precisely the point — a deliberate declaration; for others the name is simply radiant, joyful, and impossible to ignore, a name that arrives in a room before the person wearing it does.