Today's word of the day is:

 

Canker

 

Dictionary.com defines canker as:

noun

a gangrenous or ulcerous sore, especially in the mouth.

a disease affecting horses' feet, usually the soles, characterized by a foul-smelling exudate.

a defined area of diseased tissue, especially in woody stems.
something that corrodes, corrupts, destroys, or irritates.
Also called canker rose. British Dialect , dog rose.
verb
to infect with canker.
to corrupt; destroy slowly.