plural noun

: a family of freshwater blue-green algae (order Hormogonales) consisting of slender gradually attenuated or hair-tipped filaments usually growing in tufts attached to the substrate and frequently mucilaginous see calothrix , rivularia

Word History


New Latin, from Rivularia, type genus + -aceae

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!

Dictionary Entries Near Rivulariaceae

Cite this Entry

“Rivulariaceae.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Rivulariaceae. Accessed 7 Dec. 2023.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!