: a genus of large ichneumon wasps having an extremely long slender ovipositor and including a common species (M. lunator) of the eastern U.S. that is a parasite of the larva of the pigeon horntail

Word History


New Latin, from mega- + Rhyssa

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 Megarhyssa

Cite this Entry

“Megarhyssa.” Dictionary, Merriam-Webster, Accessed 15 Apr. 2024.

Love words? Need even more definitions?

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