tannin
/ˈtanɪn
/noun [mass noun]
A yellowish or brownish bitter-tasting organic substance present in some galls, barks, and other plant tissues, consisting of derivatives of gallic acid.Our perception of sweetness can be affected by a number of other factors, such as temperature, tannin and carbon dioxide, not to mention alcohol....
- To counteract intestinal discharges probably caused by the calomel, surgeons administered tannin, sulphuric acid, or morphia.
- If you take any grape - black, red or green - and slice it through the middle it looks much the same: the stalk is woody and full of a substance called tannin.
Origin
Early 19th century: from French tanin, from tan 'tanbark' (ultimately related to tan1) + -in1.
tan from Old English:
The original sense of tan is to convert skins into leather. The sense of the colour that the skin acquires after exposure to the sun dates only to the middle of the 18th century. Tan probably comes directly from Latin tannare, but may ultimately go back to a Celtic word for an oak tree. This reflects the process of tanning, whereby the crushed bark of an oak was steeped in water in which skins and hides were then immersed. Oak bark was used because it is rich in tannins (early 19th century), compounds which will tan. The related word tawny (Middle English) comes from Old French tauné, ‘tanned’.