From Longman Dictionary of Contemporary Englisha bitter pill (to swallow)a bitter pill (to swallow)UNPLEASANTsomething very unpleasant that you must accept The knowledge that his friends no longer trusted him was a bitter pill to swallow. → bitter
Examples from the Corpus
a bitter pill (to swallow)• It was a bitter pill for the 117 men listed to swallow with their Thanksgiving turkey yesterday.• Losing the business was a bitter pill to swallow.• It was a bit of a blow, a bitter pill to swallow. 