Harmful
WordNet
adjective
(1) Constituting a disadvantage
(2) Tending to cause great harm
(3) Contrary to your interests or welfare
"Adverse circumstances"
"Made a place for themselves under the most untoward conditions"
(4) Causing or capable of causing harm
"Too much sun is harmful to the skin"
"Harmful effects of smoking"
(5) Injurious to physical or mental health
"Noxious chemical wastes"
"Noxious ideas"
(6) Able or likely to do harm
WiktionaryText
Adjective
- of a kind likely to be damaging; injurious
- Wear a hat to protect your skin from harmful sunlight.