sourd

Sourd is a term used to describe a bitter or acrid taste. It is often associated with spoiled food or beverages, as the unpleasant flavor can indicate the presence of bacteria or fermentation byproducts. For example, milk that has gone sour is no longer palatable due to the development of lactic acid. Similarly, wine or beer can turn sour if exposed to air and allowed to oxidize or undergo undesirable microbial activity.

Beyond food and drink, the word "sourd" can also be used metaphorically to describe a negative or unpleasant feeling. Someone might have a "sourd" disposition, meaning they are generally grumpy or ill-tempered. In a similar vein, a situation or remark can be described as "sourd" if it is perceived as mean-spirited or unpleasant. This figurative use extends the sensory experience of bitterness to emotional and social contexts. The origin of the word "sourd" is thought to be related to the Old Norse word "súr," meaning sour or acid.