Crimson is a deep, rich red color with a slight hint of purple or blue in it. Think of the color of a ripe cherry: that intense, vibrant red is crimson. It's darker and more luxurious than fire-engine red, and more dramatic than pink.

The word often appears in descriptions of sunsets, when the sky blazes crimson as the sun drops below the horizon. Rubies shine with a crimson gleam. In medieval times, crimson fabric was expensive and rare, so kings and nobles wore crimson robes to display their wealth and power.

You'll find crimson used when writers want to emphasize that a red is especially deep or striking. A character in a story might blush crimson with embarrassment, meaning their face turned very red indeed.

The word carries a sense of richness and intensity that plain “red” doesn't quite capture. When you call something crimson instead of just red, you're saying it's a red worth paying attention to.