[adjective] injurious to physical or mental health; "noxious chemical wastes"; "noxious ideas" Synonyms:noxious
[adjective] able or likely to do harm
[adjective] causing or capable of causing harm; "too much sun is harmful to the skin"; "harmful effects of smoking"
[adjective] constituting a disadvantage Synonyms:disadvantageous
[adjective] contrary to your interests or welfare; "adverse circumstances"; "made a place for themselves under the most untoward conditions" Synonyms:adverse, inauspicious, untoward
[adjective] tending to cause great harm Synonyms:evil, injurious