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un·du·late (ŭnjə-lāt′, ŭndyə-, -də-)
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v. un·du·lat·ed, un·du·lat·ing, un·du·lates
v.intr.
1. To move in waves or with a smooth, wavelike motion: "gleaming seaweed that curls and undulates with the tide" (Willa Cather).
2. To have a wavelike appearance or form: dunes that undulate toward the sea.
3. To increase and decrease in volume or pitch.
v.tr.
1. To cause to move in a smooth wavelike motion: The dancer undulated her hips.
2. To give a wavelike appearance or form to: The rock strata are undulated.
adj. (-lĭt, -lāt′)
Having a wavy outline or appearance: leaves with undulate margins.
[From Late Latin undula, small wave, diminutive of Latin unda, wave; see wed-1 in the Appendix of Indo-European roots.]
undu·la·to′ry (-lə-tôr′ē) adj.
(click for a larger image)
undulate
undulate leaf
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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:

    Indo-European Roots

    Semitic Roots

    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.

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