n a fungal disease of woody plants that causes localized damage to the bark
n an ulceration (especially of the lips or lining of the mouth)
n a pernicious and malign influence that is hard to get rid of
v become infected with a canker
v infect with a canker
n. （植物的）溃疡( canker的名词复数 ); （动物）耳溃疡; 腐败的影响; 腐蚀因素