Canker /(kăṉ"kẽr)/

1. A corroding or sloughing ulcer; esp. a spreading gangrenous ulcer or collection of ulcers in or about the mouth; -- called also water canker, canker of the mouth, and noma.
2. Anything which corrodes, corrupts, or destroy.

   The cankers of envy and faction.

3. A disease incident to trees, causing the bark to rot and fall off. (Hort.)
4. An obstinate and often incurable disease of a horse's foot, characterized by separation of the horny portion and the development of fungoid growths; -- usually resulting from neglected thrush. (Far.)
5. A kind of wild, worthless rose; the dog-rose.

   To put down Richard, that sweet lovely rose. And plant this thorm, this canker, Bolingbroke.

imp. & p. p. Cankered; p. pr. & vb. n. Cankering

1. To affect as a canker; to eat away; to corrode; to consume.

   No lapse of moons can canker Love.

2. To infect or pollute; to corrupt.

   A tithe purloined cankers the whole estate.

1. To waste away, grow rusty, or be oxidized, as a mineral. [Obs.]

   Silvering will sully and canker more than gliding.

2. To be or become diseased, or as if diseased, with canker; to grow corrupt; to become venomous.

   Deceit and cankered malice.

   As with age his body uglier grows, So his mind cankers.