gangrene

疽 is composed of the radical of 疒(illness) and 且(and, yet). 疒 conveys the idea of disease, while 且 is the pictograph of a chopping board. When cutting meat, the chopping board is placed underneath, and meat scraps often remain on it, where bacteria can cause the scraps to rot and decay; thus 疽 refers to a disease involving necrosis or suppuration of skin and muscle tissue.