1. 1. The hue of the long-wave end of the visible spectrum, evoked in the human observer by radiant energy with wavelengths of approximately 630 to 750 nanometers; any of a group of colors that may vary in lightness and saturation and whose hue resembles that of blood; one of the additive or light primaries; one of the psychological primary hues.
   2. A pigment or dye having a red hue.
   3. Something that has a red hue.
2. 1. often Red A Communist.
   2. A revolutionary activist.

1. Having a color resembling that of blood.
2. Reddish in color or having parts that are reddish in color: a red dog; a red oak.
3. 1. Having a reddish or coppery skin color.
   2. often Red Offensive. Of or being a Native American.
4. Having a ruddy or flushed complexion: red with embarrassment.
5. often Red Communist.

in the red

1. Operating at a loss; in debt.

[Middle English, from Old English rēad.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.