From Longman Dictionary of Contemporary Englishsoursour1 /saʊə $ saʊr/ ●●● S3 adjective 1 CTSOURhaving a sharp acid taste, like the taste of a lemon or a fruit that is not ready to be eaten OPP sweet → bitter Rachel sampled the wine. It was sour. sour cherries → sweet-and-sour► see thesaurus at taste2 DFCTmilk or other food that is sour is not fresh and has a bad tasteturn/go sour (=become sour)RegisterIn everyday English, people usually say milk goes bad or, in British English, goes off, rather than goes sour.3 BAD-TEMPEREDUNFRIENDLYunfriendly or looking bad-temperedsour look/face/smile etc Eliza was tall and thin, with a rather sour face. a sour-faced old man4 informalUNPLEASANTDON'T LIKE if a relationship or plan turns or goes sour, it becomes less enjoyable, pleasant, or satisfactory As time went by, their marriage turned sour. The meeting ended on a sour note, with neither side able to reach agreement.5 → sour grapes —sourly adverb —sourness noun [uncountable]
Examples from the Corpus
sour• The vision of bedsit freedom would soon turn sour.• The milk smells a little sour.• These cherries are really sour.• In 1993, a wage garnishment was filed against him stemming from a diamond sale gone sour.• What is sour comes from pretending to be what we are not.• She always had the same sour expression.• The minute the sour flavor exploded in his mouth, slivers of intense pain filled his head.• Kvass is a mild beer that is sometimes used in Russian cooking for its sour flavor.• I smelt the sour odour of sweaty robes and noticed a brazier of gleaming charcoal had been rolled in.• Too often relationships go sour or become impoverished through lack of attention.• Soon he would smell the first sour tang of winter on the sea breezes.• The wine was so sour that I couldn't drink it.• In these temperatures, milk goes sour very quickly.• The strawberries are a little sour - you may need to put sugar on them.turn/go sour• We dated two years and then things went sour.• I see the play as an extension of that idea: a study of what happens when idealism goes sour.• In 1993, a wage garnishment was filed against him stemming from a diamond sale gone sour.• In this case, the relationship turned sour.• The deal went sour and Coles lost A $ 18 million.• Many of the deals struck in this frenzied atmosphere are sure to go sour eventually, sending more companies to the brink.• Liberation has turned sour producing anomie and alienation, severely undermining any sense of collective responsibility or response.• A settling of accounts, a drug deal that went sour, rival protection racketeers?• But things have turned sour since those days of promise.sour look/face/smile etc• She looked back over her shoulder at him and pulled a sour face.• I told you my brother prefers smiles to sour looks, and so he too likes my choice.• A Tory campaign machine on full throttle generally encountered sour looks and sullen stares.sour note• From workers there's bitterness that it's all ended on such a sour note.• The craftsmen there hope their careers won't end on a sour note.• This needled Stirling and the meeting ended on a sour note.• Yet it would be wrong to end on a sour note.• The only slightly sour note entered the proceedings with the president's plan to send a special envoy to Northern Ireland.• But it was here that the first sour note in the melodious anthem was heard.• If the player tampers with those, he is blamed for hitting a sour note, not praised for a daring interpretation.• The only sour note was the electrified fence that marked the forbidden border zone.soursour2 verb [intransitive, transitive] 1 SPOILif a relationship or someone’s attitude sours, or if something sours it, it becomes unfriendly or unfavourable An unhappy childhood has soured her view of life.► see thesaurus at spoil2 DFDECAYif milk sours, or if something sours it, it begins to have an unpleasant sharp taste→ See Verb tableExamples from the Corpus
sour• Since each of these parties leant on the other for reassurance, relations between them will be soured as a result.• That was still before people went to chokey for dodgy dealings, but he soured his own patch.• Ill-treated hobgoblins can cause strife and discord, though, souring milk, tangling clothes and muddying floors for spite.• Many investors have soured on closedend funds because they were burned buying closed-end IPOs.• Worth noting about McMahon, though, is that some teams reportedly soured on his attitude at the Senior Bowl.• The incident soured relations between the two countries.• The global trend towards higher taxation on fuel consumption is souring relations with leading oil-producing states.• The incident was serious enough to sour the atmosphere for weeks.• The affair did not seem to have soured their friendship.• The familiar dark soured then stung with chlorine.Origin sour1 Old English sur 