Meaning & Definition
adjective
Causing or capable of causing damage or injury.
The chemicals in that product are harmful to the environment.
Having a negative effect on health or well-being.
Excessive sugar consumption can be harmful to your health.
Destructive or hurtful in nature.
The rumor spread by the gossip was harmful to her reputation.
Tending to cause physical or psychological harm.
Secondhand smoke is known to be harmful to children.
Detrimental or unfavorable.
Lack of sleep can have harmful effects on cognitive function.
Etymology
Middle English: from harm + -ful.
Common Phrases and Expressions
harmful effects:
negative consequences that can cause damage or suffering.
harmful environment:
a setting that poses dangers or risks to health and safety.
harmful substances:
materials that can cause damage to living organisms.
Slang Meanings
bad for you
Those junk foods are really bad for you, totally harmful.
toxic
That relationship became so toxic, it was harmful to my mental health.