primary rainbow


noun
  1. the most commonly seen rainbow, formed by light rays that undergo a single internal reflection in a drop of water.

Origin of primary rainbow

1
First recorded in 1785–95

Words Nearby primary rainbow

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use primary rainbow in a sentence

  • The ordinary or primary rainbow has a radius of about 42 degrees at its outer edge.

    Meteorology | Charles Fitzhugh Talman