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
2
a(1)
: having the acid taste or smell of or as if of fermentation : turned
sour milk
(2)
: of or relating to fermentation
b
: smelling or tasting of decay : rancid, rotten
sour breath
c(1)
: bad, wrong
a project gone sour
(2)
: hostile, disenchanted
went sour on Marxism
3
b
c
: not up to the usual, expected, or standard quality or pitch
4
: acid in reaction
used especially of soil
5
: containing malodorous sulfur compounds
used especially of petroleum products
sourish adjective
sourly adverb
sourness noun

sour

2 of 3

noun

1
a
: 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

3 of 3

verb

soured; souring; sours

intransitive verb

: to become sour

transitive verb

: to make sour

Examples of sour in a Sentence

Adjective The milk had turned sour. He made a sour face. Verb Her disposition has soured in recent years. Jealousy has soured their relationship. His experiences have soured him. The team's victory was soured by an injury to one of their best players.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Adjective
Your bag should include something with strong tastes like sour, bitter, or salty to stimulate the vagus nerve at the back of the tongue, which may help promote a calming effect. Nicole Cain, Harvard Business Review, 23 Oct. 2024 The gist: Slightly sour juicy fruit soaks into a batter of heavy butter, sugar and eggs, creating a sturdy dessert. Monica Eng, Axios, 13 Oct. 2024
Noun
Arika loved the Barn Storm, a tropical sour made especially for the Minnesota State Fair. Lindsey Erdody, Axios, 24 Sep. 2024 The Leo new moon on August 4 is the time to embrace the good and the bad, the sweet and the sour, and find a middle ground between these extremities. Lisa Stardust, refinery29.com, 2 Aug. 2024
Verb
Meanwhile, enthusiasm for Harris has soured among black voters in Pennsylvania, a state both presidential campaigns have said is critical to winning the election. Emily Hallas, Washington Examiner - Political News and Conservative Analysis About Congress, the President, and the Federal Government, 28 Oct. 2024 Even the most devout relationships can sour over money. Brian Welk, IndieWire, 25 Oct. 2024 See all Example Sentences for sour 

Word History

Etymology

Adjective

Middle English, from Old English sūr; akin to Old High German sūr sour, Lithuanian sūrus salty

First Known Use

Adjective

before the 12th century, in the meaning defined at sense 1

Noun

before the 12th century, in the meaning defined at sense 1a

Verb

14th century, in the meaning defined at intransitive sense

Time Traveler
The first known use of sour was before the 12th century

Dictionary Entries Near sour

Cite this Entry

“Sour.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sour. Accessed 21 Nov. 2024.

Kids Definition

sour

1 of 3 adjective
1
: having or being an acid or tart taste that is one of the four taste sensations compare bitter sense 1, salt entry 3 sense 1b, sweet entry 1 sense 1b
2
a
: having become acid through spoiling
sour milk
b
: indicating decay : putrid
a sour odor
3
: unpleasant, disagreeable
a sour look
played a sour note
4
: acid in reaction
sour soil
sourly adverb
sourness noun

sour

2 of 3 noun
1
a
: something sour
b
: the basic taste sensation produced by acid stimuli
2
: a cocktail made with liquor, lemon or lime juice, sugar, and sometimes soda water

sour

3 of 3 verb
: to become or make sour

Medical Definition

sour

1 of 2 adjective
: causing, characterized by, or being the one of the four basic taste sensations that is produced chiefly by acids compare bitter, salt entry 2 sense 2, sweet entry 1
sourness noun

sour

2 of 2 noun
: the primary taste sensation produced by acid stimuli

More from Merriam-Webster on sour

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!