(1):

(v. t.) To cause to fester; to make sore; to inflame.

(2):

(a.) To become, or be, rank; to grow rank or strong; to be inflamed; to fester; - used literally and figuratively.

(3):

(a.) To produce a festering or inflamed effect; to cause a sore; - used literally and figuratively; as, a splinter rankles in the flesh; the words rankled in his bosom.