plural noun Thy·ros·tra·ca \thīˈrästrəkə\

Definition of Thyrostraca

in some especially former classifications

  1. :  a subclass of Crustacea coextensive with Cirripedia


adjective or noun

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 thyrostraca

New Latin, from thyro- (from Greek thyra door, opening) + Greek ostraka, plural of ostrakon shell — more at door, oyster

Seen and Heard

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


a rounded knoll or a ridge of ice

Get Word of the Day daily email!