to treat an illness; to cure; to apply medicine; to counteract, as in the phrase 以毒攻毒 yǐ​dú​gōng​dú

(bound form) an ancient stone needle used for acupuncture or to pierce the skin to treat illnesses

to accuse; to censure; to find fault with and criticize others

(bound form) to criticize sharply or point out mistakes in order to correct them