n. (used with a sing. or pl. verb)
a. An acute, contagious viral disease, usually occurring in childhood and characterized by eruption of red spots on the skin, fever, and catarrhal symptoms. Also called rubeola.
b. Black measles.
c. Any of several other diseases, especially German measles, that cause similar but milder symptoms.
2. A condition of pork or beef caused by the presence of tapeworm larvae.
3. A plant disease, usually caused by fungi, that produces small spots on leaves, stems, or fruit.
[Middle English maseles, mesels, pl. of masel, measles-spot, of Middle Low German origin.]
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:
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.