Rainbow
/ˈreɪn.boʊ/noun
An arc of colors seen in the sky when sunlight is refracted and reflected by water droplets.
Did you know?In Old English, the word was literally a compound for a rain-made arch, and many cultures treated that arch as a bridge, omen, or divine sign.
Etymological Timeline
Proto-Indo-European
PIE
*bheug-
“to bend, curve”
Old English
OE
regnbeag
“rain-bow, rain-made arch”
Middle English
ME
rainbowe
“rainbow, the colored arc in the sky”
Modern English
English
rainbow
“the arc of colors caused by refraction and reflection of sunlight in water droplets”