RANK'LE, verb intransitive [from rank.] 1. To grow more rank or strong; to be inflamed; to fester; as a rankling wound. A malady that burns and rankles inward. 2. To become more violent; to be inflamed; to rage; as rankling malice; rankling envy. Jealousy rankles in the breast.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI