Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary


noun glo·chid·i·um \glō-ˈki-dē-əm\

Definition of glochidium



  1. :  the larva of a freshwater mussel (family Unionidae) that develops as an external parasite on fish

Origin and Etymology of glochidium

New Latin, from Greek glōchis projecting point + New Latin -idium

First Known Use: 1875

Learn More about glochidium

Seen and Heard

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