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pla·teau (plă-tō)
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n. pl. pla·teaus or pla·teaux (-tōz)
1. An elevated, comparatively level expanse of land; a tableland.
2. A relatively stable level, period, or state: Mortgage rates declined, then reached a plateau.
intr.v. pla·teaued, pla·teau·ing, pla·teaus
To reach a stable level; level off: "The tension seemed to grow by degrees, then it plateaued" (Tom Clancy).
[French, from Old French platel, platter, from plat, flat; see PLATE.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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:

    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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