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asth·ma (ăzmə, ăs-)
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n.
A chronic inflammatory disease of the lungs characterized by a narrowing of the airways and attacks of wheezing, coughing, and shortness of breath that are induced by triggers such as allergens, exercise, infections, and stress.
[Middle English asma, from Medieval Latin, from Greek asthma.]
asth·matic (-mătĭk) adj. & n.
asth·mati·cal·ly adv.
(click for a larger image)
asthma
left: inflamed bronchial tube with contracted muscles and mucus discharge
right: normal bronchial tube
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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