sour
UK[ˈsaʊə(r)]US[ˈsaʊər]
adj
having a sharp, acidic taste like that of a lemon or vinegar.
adj
(of food or drink) having gone bad because of fermentation, often having a sharp, unpleasant taste.
adj
(of a person's mood or attitude) bad-tempered, unfriendly, or resentful.
v
to become or make something become sour in taste or mood.
Etymology
the word 'sour' descends directly from the old english adjective 'sūr', which meant 'acidic, tart'. this old english term has cognates in other germanic languages, such as old norse 'súrr' and dutch 'zuur', all pointing to a common proto-germanic ancestor 'sūraz'. this proto-germanic root is further traced back to the proto-indo-european base 'sūro-', meaning 'sour, salty, bitter'. the semantic journey is straightforward, with the core meaning of an acidic taste remaining remarkably stable for millennia. the figurative extension to describe a disagreeable mood or disposition, first recorded in the late 14th century, is a natural metaphorical leap, linking a sharp taste to a sharp temperament.
Analysis
the word is a simplex of old english origin. it is not productively formed from smaller, independent morphemes in modern english.
Examples
the lemonade was too sour for the children's liking.
the milk had turned sour after being left out all night.
the long dispute soured their previously friendly relationship.