Definition of cankers:
(n) :
Anything which corrodes, corrupts, or destroys.
(n) :
A corroding or sloughing ulcer; especially a spreading gangrenous ulcer or collection of ulcers in or about the mouth.
(v) :
(transitive) To infect or pollute; to corrupt.
(v) :
(transitive) To affect as a canker; to eat away; to corrode; to consume.
(v) :
(intransitive) To be or become diseased, or as if diseased, with canker; to grow corrupt; to become venomous.
(n) :
(phytopathology) A plant disease marked by gradual decay.