- 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.
- A pigment or dye having a red hue.
- Something that has a red hue.
- often Red A Communist.
- A revolutionary activist.
- Having a color resembling that of blood.
- Reddish in color or having parts that are reddish in color: a red dog; a red oak.
- Having a reddish or coppery skin color.
- often Red Offensive. Of or being a Native American.
- Having a ruddy or flushed complexion: red with embarrassment.
- often Red Communist.
in the red
- Operating at a loss; in debt.
[Middle English, from Old English rēad.]
redly red'ly adv.redness red'ness n.

