\ ˈsau̇(-ə)r How to pronounce sour (audio) \

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
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
b : cross, sullen
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



Definition 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


soured; souring; sours

Definition of sour (Entry 3 of 3)

intransitive verb

: to become sour

transitive verb

: to make sour

Other Words from sour


sourish \ ˈsau̇(-​ə)r-​ish How to pronounce sour (audio) \ adjective
sourly adverb
sourness noun

Synonyms & Antonyms for sour

Synonyms: Adjective

Synonyms: Verb

Antonyms: Verb

Visit the Thesaurus for More 

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.
See More
Recent Examples on the Web: Adjective There are roughly 605 million barrels of sweet and sour petroleum in the reserve. Josh Boak And Colleen Long, Anchorage Daily News, 23 Nov. 2021 The tomahawk pork chop ($38) is first brined then smoked and grilled and served with a large portion of Yukon Gold potatoes, sweet-and-sour peppers and hot Creole mustard. John Mariani, Forbes, 26 Oct. 2021 King’s Ransom, a semi-soft, cider-washed cow’s milk wheel made in Wisconsin, plugs easily into a mix of winter squashes given a sweet and sour treatment. Bill Addison, Los Angeles Times, 15 Oct. 2021 The pork comes out blissfully juicy, with a delightful sweet-and-sour edge. Tribune News Service, cleveland, 25 Aug. 2021 The key was finding a collaborator who sticks with me through the sweet and sour. Michael Schneider, Variety, 29 Sep. 2021 It’s garlic-y and has sweet and sour molasses with tons of local herbs. Dawn Davis, Bon Appétit, 16 Sep. 2021 Mohanraj points to other Southeast Asian imprints on the cuisine too: lemongrass, coconut milk, red rice, tamarind, and importantly, a balance of salty, sour and sweet flavors. Tina Danze, Dallas News, 13 Oct. 2020 Consumers are puckering up for sour food and drinks of all sorts. Chris Woodyard, USA TODAY, 11 Apr. 2018 Recent Examples on the Web: Noun In just over three minutes, Phair manages to capture the agony and discomfort of a relationship that’s just beginning to sour. Emma Specter, Vogue, 18 Nov. 2021 This gift basket includes the typical local products of Lombardy, from saffron risotto and the traditional holiday panettone cake, to the sweet amaretti cookies and sweet-and-sour fig mostarda. Irene S. Levine, Forbes, 1 Nov. 2021 The decorated drink features Lunazul Silver tequila, triple sec, fresh sour, blood orange syrup and a spider ring. Sabrina Weiss,, 14 Oct. 2021 Even during these tough times, the debates about sweet vs. sour, chocolate vs. gummy, candy corn pro or con are always topics friends and family can feud over -- and there are never any hard feelings. John Canale, cleveland, 7 Oct. 2021 Chili’s has brought back their Spiderbite 'Rita, which is made with Lunazul Silver Tequila, Triple Sec, fresh sour, blood orange syrup and decorated with a spooky spider ring. Aly Walansky, Forbes, 5 Oct. 2021 Robert DaRosa and Steven David, owners of Smug Brewery in Pawtucket, made 20 barrels of the imperial sour just for this weekend’s game., 1 Oct. 2021 The enthusiastic celebration and the warmth exchanged between the teams — so rarely seen now as US-China relations and public sentiment sour — quickly went viral online. Aya Elamroussi, CNN, 6 Aug. 2021 The sweet-chili sauce tasted like hard candy spiked with red-pepper flakes and reminded me of my favorite McDonald’s sauce growing up: sweet-and-sour. New York Times, 14 July 2021 Recent Examples on the Web: Verb Excitement initially rippled across Japan but the public's perceptions began to sour shortly afterwards. CNN, 26 Oct. 2021 The country had begun to sour as the Iraq War continued deteriorating abroad, and in late August the country turned against George W. Bush domestically for a disastrous response to Hurricane Katrina. Walter Shapiro, The New Republic, 22 Oct. 2021 Any amount of customer uncertainty or discomfort can sour an otherwise positive purchase experience, prompting customers who could have become loyal lifetime brand ambassadors to take their business elsewhere next time. Adrian Swinscoe, Forbes, 14 Sep. 2021 However, confidence gone wrong can sour into lethargy, arrogance or distractedness against weaker teams. Marie Schulte-bockum, Forbes, 13 Oct. 2021 Meanwhile, investors started to sour on the insurtech industry. Jeff Kauflin, Forbes, 30 Sep. 2021 If the curve flattens further, Wall Street will sour, the stock price will drop and Disney would be motivated to employ other tactics to boost the curve upward again. Gene Del Vecchio, Variety, 30 Aug. 2021 This condescension has done a lot to sour disabled people’s feelings about politics, despite other undeniable gains. Andrew Pulrang, Forbes, 18 Sep. 2021 But the relationship began to sour in 2017 when Epic released Fortnite. Malathi Nayak, Time, 11 Sep. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sour.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of sour


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


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


14th century, in the meaning defined at intransitive sense

History and Etymology for sour


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

Learn More About sour

Time Traveler for sour

Time Traveler

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

See more words from the same century

Dictionary Entries Near sour



sour ball

See More Nearby Entries 

Statistics for sour

Last Updated

25 Nov 2021

Cite this Entry

“Sour.” Dictionary, Merriam-Webster, Accessed 7 Dec. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for sour



English Language Learners Definition of sour

 (Entry 1 of 3)

: having an acid taste that is like the taste of a lemon : tart
: having the unpleasant taste or smell of food that is no longer fresh
: unpleasant or unfriendly



English Language Learners Definition of sour (Entry 2 of 3)

: an alcoholic drink that has a sour taste



English Language Learners Definition of sour (Entry 3 of 3)

: to lose freshness and get an unpleasant taste or smell : to become sour
: to become unpleasant or unfriendly
: to make (someone or something) unpleasant or unfriendly


\ ˈsau̇r How to pronounce sour (audio) \
sourer; sourest

Kids Definition of sour

 (Entry 1 of 2)

1 : having an acid or tart taste a sour fruit
2 : having spoiled : not fresh sour milk
3 : suggesting decay a sour smell
4 : not pleasant or friendly a sour look

Other Words from sour

sourly adverb He looked at me sourly enough but said nothing. — Robert Louis Stevenson, Treasure Island


soured; souring

Kids Definition of sour (Entry 2 of 2)

1 : to make or become acid or tart in taste (as by spoiling) The milk soured.
2 : to lose or cause to lose interest or enthusiasm He soured on trying new stunts following the mishap.
3 : to harm or damage The misunderstanding soured their friendship.


\ ˈsau̇(ə)r How to pronounce sour (audio) \

Medical Definition of sour

 (Entry 1 of 2)

: 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

Other Words from sour

sourness noun



Medical Definition of sour (Entry 2 of 2)

: the primary taste sensation produced by acid stimuli

More from Merriam-Webster on sour

Nglish: Translation of sour for Spanish Speakers

Britannica English: Translation of sour for Arabic Speakers


Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
True or False

Test your knowledge - and maybe learn something along the way.

Love words? Need even more definitions?

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