harm·ful adj: of a kind likely to cause harmharm·ful·ly advharm·ful·ness n
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.
afflicting, bad, baleful, baneful, calamitous, cataclysmic, catastrophic, consuming, consumptive, corrosive, costly, crippling, cruel, crushing, damaging, dangerous, deleterious, destructive, detracting, detrimental, devouring, dire, disadvantageous, disastrous, disserviceable, evil, fell, fiendish, foul, hurtful, ill-intentioned, inexpedient, infectious, injurious, insalubrious, insidious, internecine, malefic, maleficent, malicious, malign, mephitic, merciless, miasmal, mischievous, morbific, nasty, nocens, nocent, nocuous, noisome, noxious, noxius, pernicious, pestiferous, pestilential, pitiless, poisonous, polluted, ruinous, spiteful, subversionary, subversive, toxic, treacherous, troublous, unfavorable, unfortunate, unhealthy, unlucky, unpropitious, unsafe, unwholesome, venomous, vicious, wicked, wounding
associated concepts: harmful consequences from an overt act, harmful products
adverse (negative), dangerous, deleterious, destructive, detrimental, disadvantageous, disastrous, fatal, hostile, inadvisable, incendiary, inimical, insalubrious, invidious, lethal, malevolent, malicious, malignant, noxious, oppressive, outrageous, painful, peccant (unhealthy), pernicious, pestilent, prejudicial, scathing, sinister, toxic, virulent
Burton's Legal Thesaurus. William C. Burton. 2006