noun hy·dro·the·ca

Definition of hydrotheca

  1. :  a cup-shaped extension of the perisarc in hydroids of the group Leptomedusae that surrounds and protects the hydranths when they are contracted



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.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of hydrotheca

New Latin, from hydr- + Latin theca sheath, case — more at tick

Seen and Heard

What made you want to look up hydrotheca? Please tell us where you read or heard it (including the quote, if possible).


feeling or affected by lethargy

Get Word of the Day daily email!