intransitive verb, transitive verb rankled -·kled, rankling -·kling

1. Obsolete to fester; become or make inflamed
2. to cause or cause to have long-lasting anger, rancor, resentment, etc. their indifference rankled him

Etymology: ME ranclen < OFr rancler < raoncle, draoncle, a fester, ulcer < ML dracunculus < L, dim. of draco, dragon