v. ra·di·at·ed, ra·di·at·ing, ra·di·ates
1. To send out rays or waves.
2. To issue or emerge in rays or waves: Heat radiated from the stove.
3. To extend in straight lines from or toward a center; diverge or converge like rays: Spokes radiate from a wheel hub.
4. To spread into new habitats and thereby diverge or diversify. Used of a group of organisms.
1. To emit (light or energy) in rays or waves.
2. To send or spread out from or as if from a center: a cactus that radiates spines.
3. To irradiate or illuminate (an object).
4. To manifest in a glowing manner: a leader who radiates confidence.
1. Botany Having rays or raylike parts, as in the flower heads of daisies.
2. Biology Characterized by radial symmetry.
3. Surrounded with rays: a radiate head on a coin.
[Latin radiāre, radiāt-, to emit beams, from radius, ray; see RAY1.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.