a. The hue of that portion of the visible spectrum lying between orange and green, evoked in the human observer by radiant energy with wavelengths of approximately 570 to 590 nanometers; any of a group of colors of a hue resembling that of ripe lemons and varying in lightness and saturation; one of the subtractive primaries; one of the psychological primary hues.
b. A pigment or dye having this hue.
c. Something that has this hue.
2. Chiefly Southern US The yolk of an egg.
3. Western US Gold. Used formerly by prospectors.
4. yellows Any of various plant diseases characterized by yellow or yellowish discoloration of the leaves and caused by phytoplasmas that are transmitted by insects or by certain viruses.
adj. yel·low·er, yel·low·est
1. Of the color yellow.
a. Having a yellow-brown skin color.
b. Offensive Of or being a person of Asian origin.
3. Slang Cowardly.
tr. & intr.v. yel·lowed, yel·low·ing, yel·lows
To make or become yellow: documents that had been yellowed by age; clouds that yellow in the evening light.
[Middle English yelow, from Old English geolu; see ghel-2 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.