Quizzes & Games
Word of the Day
Video
New Words
My Favorites
View your list of saved words.
(You can log in using Facebook.)

ammonium alum

noun

Definition of AMMONIUM ALUM

: alum 1b

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

Take Our 10-Question Quiz

Hear It, Spell It »

Take It Now »

Take the Quiz »

Get Our Free Apps

Voice Search, Favorites,
Word of the Day, and More

iPhone | iPad | Android | More

Join Us on FB & Twitter

Get the Word of the Day and More

Facebook | Twitter

The Merriam-Webster
Unabridged Dictionary

Online access to a
legendary resource
Log In or Sign Up »

Learning English?
We can help.

Visit our free site designed
especially for learners and
teachers of English
LearnersDictionary.com »

Our Dictionary,
On Your Devices

Merriam-Webster,
With Voice Search
Get the Free Apps! »

Merriam-Webster's
Visual Dictionaries

The new edition of the
remarkable reference
features 8,000
illustrations.
Learn More »

Join Us

Bookstore: Digital and Print

Merriam-Webster references for Mobile, Kindle, print, and more. See all »

Other Merriam-Webster Dictionaries

Browse the Dictionary

Browse the Thesaurus

Browse the Spanish-English Dictionary

Browse the Medical Dictionary

Browse the Concise Encyclopedia