[] to change and become more difficult or less pleasant or friendly; to make sth do this（使）变坏，恶化◆What will happen if the economy sours?如果经济形势恶化，将会怎么样？◆Weak job prospects soured spirits.疲软的工作前景使士气低落。●go/turn ˈsourto become unpleasant or bad; to fail变坏；恶化◆The deal started to go sour.这笔交易开始出现问题。