Wordnet 3.0
VERB (1)
1. 
 gnaw into; 
 make resentful or angry; 
- Example: "The injustice rankled her"- Example: "his resentment festered"[syn: eat into, fret, rankle, grate]
WordNet (r) 3.0 (2006):
eat into
    v 1: gnaw into; make resentful or angry; "The injustice rankled
         her"; "his resentment festered" [syn: eat into, fret,
         rankle, grate]