Hydrachnidae

plural noun

Hy·​drach·​ni·​dae

-nəˌdē

in some classifications

: a large family of water mites (group Hydrachnellae) that includes all the common free-living mites of fresh water and a few parasites of the gills of mollusks and that is now usually broken up into numerous separate families

Word History

Etymology

New Latin, from Hydrachna, type genus (from hydr- + Greek achna, achnē foam, chaff) + -idae

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!