Synonyms to bitter pill

acerbity, acescency, acid, acidity, acidness, acidulousness, acridity, acridness, acrimony, animosity, asperity, astringence, astringency, bile, bite, bitingness, bitter resentment, bitterness, bitterness of spirit, causticity, causticness, choler, corrosiveness, crabbedness, cuttingness, dourness, dryness, edge, fierceness, gall, gall and wormwood, gnashing of teeth, greenness, grip, hard feelings, harshness, heartburning, hyperacidity, incisiveness, keenness, mordacity, mordancy, piercingness, piquancy, poignancy, point, pungency, rancor, rankling, rigor, roughness, severity, sharpness, slow burn, soreness, sour, sourishness, sourness, spleen, stabbingness, sting, stridency, stringency, subacidity, surliness, tartishness, tartness, teeth, trenchancy, unripeness, unsweetness, vehemence, verjuice, vinegariness, vinegarishness, violence, virulence, acuity, acumination, acuteness, fierce