n. pl. fi·lar·i·ae (-ē-ē′)
Any of various slender, threadlike nematode worms of the superfamily Filarioidea that are parasitic in vertebrates and are often transmitted as larvae by mosquitoes and other biting insects. Infestation with different species of filariae cause diseases such as lymphatic filariasis (which can lead to elephantiasis) and onchocerciasis.
[New Latin Fīlāria, former genus name, from Latin fīlum, thread; see gwhī- in the Appendix of Indo-European roots.]
fi·lari·al (-ē-əl), fi·lari·an (-ē-ən) adj.
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:
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.