plural alkalies or alkalis
Definition of alkali
1
: a soluble salt obtained from the ashes of plants and consisting largely of potassium or sodium carbonate
broadly
: a substance (such as a hydroxide or carbonate of an alkali metal) having marked basic properties — compare base sense 6a
2
: alkali metal
3
: a soluble salt or a mixture of soluble salts present in some soils of arid regions in quantity detrimental to agriculture
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
The Exceptions Quiz III
-
- Which of these words does not mean "nonsense"?

Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Anagram puzzles meet word search.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Words at Play
Ask the Editors
Word Games
Share alkali
Time Traveler for alkali
The first known use of alkali was in the 14th century
See more words from the same century