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:
What made you want to look up Mactra? Please tell us where you read or heard it (including the quote, if possible).
Test your knowledge of food vocabulary!
Take the quiz
Is that your picture under "Largest Vocabulary"?
Take the quiz
Can you spell these 10 commonly misspelled words?
Take the quiz
The dictionary has been scrambled—can you put it back together?
Play the game
