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stim·u·lus (stĭmyə-ləs)
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n. pl. stim·u·li (-lī′)
1. Something causing or regarded as causing a response.
2. An agent, action, or condition that elicits or accelerates a physiological or psychological activity or response.
3.
a. Something that incites or rouses to action; an incentive: "Works which were in themselves poor have often proved a stimulus to the imagination" (W.H. Auden).
b. Government spending designed to generate or increase economic activity.
[Latin, goad.]
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:

    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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