B2adjective2K

Harmful

UK /["/ˈhɑːmfl/"]/US /["/ˈhɑːrmfl/"]/

Definition

causing damage or injury to somebody/something, especially to a person’s health or to the environment

In simple words: something that can hurt or cause damage

Examples

  • The chemicals in that product are potentially harmful to your health.
  • Exposure to harmful radiation can lead to serious health issues.
  • Eating too much sugar can be harmful to your teeth and overall health.
  • Certain species can be harmful to local ecosystems if introduced.
  • The harmful effects of smoking are widely documented.

Usage notes

Use 'harmful' when discussing things that can negatively affect health or well-being. It's suitable in both written and spoken contexts, such as warnings or discussions about products.

Grammar pattern

harmful + object

Memory hint

Think of 'harm' + 'ful' — something that is full of harm.

Collocations

  • be
  • prove
  • become
  • extremely
  • very
  • particularly
  • to

Synonyms

  • detrimental
  • injurious
  • noxious
  • dangerous
  • destructive

Antonyms

  • beneficial
  • harmless

Common mistakes

  • Used incorrectly with non-physical subjects (e.g., saying 'harmful idea')
  • Confused with 'harmless'
  • Omitted 'to' in phrases like 'harmful to health'