Source : Webster's Revised Unabridged Dictionary (1913)

Canker \Can"ker\ (k[a^][ng]"k[~e]r), v. t. [imp. & p. p.
   {Cankered} (-k[~e]rd); 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.    --Tennyson.

   2. To infect or pollute; to corrupt. --Addison.

            A tithe purloined cankers the whole estate.
                                                  --Herbert.

Cankered \Can"kered\, a.
   1. Affected with canker; as, a cankered mouth.

   2. Affected mentally or morally as with canker; sore,
      envenomed; malignant; fretful; ill-natured. ``A cankered
      grandam's will.'' --Shak.