From Longman Dictionary of Contemporary Englishsugar/sweeten the pillsugar/sweeten the pillNICEto do something to make an unpleasant job or situation less unpleasant for the person who has to accept it → pill
Examples from the Corpus
sugar/sweeten the pill• They tried to sweeten the pill. b. They tried to sugar the medicine. 34a.• To sweeten the pill, the government will try to boost the flagging economy in various ways. 