noun ae·quo·rin \ēˈkwȯrə̇n, -ōr-\

Definition of aequorin



  1. :  a bioluminescent protein of jellyfish (genus Aequorea) that emits light in response to the addition of calcium or strontium and is used to demonstrate the presence and distribution of calcium in cells

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 aequorin

New Latin Aequorea aequorea + 1-in

First Known Use: 1962

Seen and Heard

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


a brief usually trivial fact

Get Word of the Day daily email!