Mactridae

plural noun

Mac·​tri·​dae

-rəˌdē

: a widely distributed family of marine clams (suborder Tellinacea) that have closely fitting or slightly gapping shells with two cardinal teeth in each valve and fused ensheathed siphons of equal length and that comprise the surf clams compare lutraria , mactra, spisula

Word History

Etymology

New Latin, from Mactra, type genus + -idae

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!