donation. 1  an act or instance of presenting something as a gift, grant, or contribution. 2  a gift, as to a fund; contribution.
A black or brown tongue typically is due to the overgrowth of bacteria that normally are present on the tongue. This, too, can be caused by the killing of some bacteria with antibiotics so other bacteria overgrow. But the most common cause of discoloration of the tongue is the overgrowth of a fungus. The most common fungus is called candida. But overgrowth of the candida fungus turns the tongue white. Infection with candida is called candidiasis, and when it happens on the tongue the condition is called thrush.
Every now and then you notice that your tongue (usually a healthy pink) is coated in white. While a white tongue is something that can be alarming, there is no need to worry. Most of the time, the cause of a white tongue is harmless and temporary. The surface of your tongue is covered with papillae. If your tongue is entirely coated in white, you are likely to have an inflammation of the papillae that is caused by dead bacteria, debris and dead cells getting stuck among them.