acerb, acerbate, acerbic, acid, acidic, acidulent, acidulous, acrid, acrimonious, acute, antagonistic, antipathetic, astringent, baleful, baneful, belligerent, biting, bitter, brutal, burning, catching, caustic, choleric, clashing, colliding, communicable, conflicting, contagious, corroding, corrosive, corrupting, corruptive, counterproductive, cutting, damaging, dangerous, deadly, death-bringing, deathful, deathly, deleterious, despiteful, destructive, detrimental, disadvantageous, disserviceable, distressing, double-edged, drastic, edged, embittered, envenomed, escharotic, excessive, exorbitant, extravagant, extreme, fatal, feral, fierce, full of hate, furious, great, harmful, harsh, hateful, hostile, hurtful, immoderate, incisive, infectious, infective, injurious, intemperate, intense, internecine, keen, killing, lethal, malefic, malevolent, malicious, malign, malignant, mephitic, miasmal, miasmatic, miasmic, mischievous, mordacious, mordant, mortal, nasty, noisome, noxious, ominous, outrageous, penetrating, pernicious, pestiferous, pestilential, piercing, poignant, poison, poisonous, prejudicial, quarrelsome, rancorous, rankled, repugnant, resentful, resenting, rigorous, rough, sarcastic, savage, scatheful, scathing, septic, set against, severe, sharp, sore, spiteful, splenetic, splitting, stabbing, stewing, stinging, strident, stringent, tart, tough, toxic, toxicant, toxiferous, trenchant, unconscionable, unfriendly, unhealthy, unwholesome, vehement, venenate, veneniferous, venenous, venomous, vicious, violent, vitriolic