Definition of sour
(Entry 1 of 3)
1
: being, inducing, or marked by the one of the five basic taste sensations that is produced chiefly by acids and is characteristic of lemon juice
sour pickles
— compare bitter entry 1 sense 1a, salty entry 1 sense 1b, sweet entry 1 sense 1, umami entry 2
2a(1)
: having the acid taste or smell of or as if of fermentation : turned
sour milk
(2)
: of or relating to fermentation
(2)
: hostile, disenchanted
went sour on Marxism
4
: acid in reaction
—used especially of soil
5
: containing malodorous sulfur compounds
—used especially of petroleum products
sour
nounDefinition of sour (Entry 2 of 3)
1a
: something sour
… they assimilated many Anglo-American sweet pickles and began adding more sugar to their sours.— William Woys Weaver
b
: the taste sensation produced chiefly by acids — compare bitter entry 2 sense 1b, salty entry 2, sweet entry 3 sense 2, umami entry 1
2
: a cocktail consisting of a liquor (such as whiskey), lemon or lime juice, sugar, and sometimes ice
sour
verb
soured; souring; sours
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Keep scrolling for more
Test Your Vocabulary
The Exceptions Quiz III
-
- Which of these words does not mean "nonsense"?

Test your visual vocabulary with our 10-question challenge!
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
Share sour
Time Traveler for sour
The first known use of sour was before the 12th century
See more words from the same century