plural noun

: a family of parasitic fungi (order Peronosporales) in which the conidiophores form outside the epidermis of the host and develop conidia or sporangia singly or in clusters but never in chains see downy mildew

Word History


New Latin Peronospora, 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 Peronosporaceae

Cite this Entry

“Peronosporaceae.” Dictionary, Merriam-Webster, Accessed 30 May. 2024.

Love words? Need even more definitions?

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