1. causing or capable of causing harm

- too much sun is harmful to the skin

- harmful effects of smoking

Similar word(s): disadvantageous, unfavorable, unfavourable, malign, destructive, abusive, bad, bruising, deleterious, hurtful, injurious, calumniatory, calumnious, defamatory, denigrating, denigrative, denigratory, libellous, libelous, slanderous, catastrophic, ruinous, counterproductive, damaging, detrimental, prejudicial, prejudicious, ill, insidious, pernicious, subtle, mischievous, nocent, stabbing, wounding, noxious, offensive, painful, toxic, unwholesome

Sentences with harmful as an adjective:

- Wear a hat to protect your skin from harmful sunlight.