# harmful

/ˈhɑɹmfəɫ/ (US) · /hˈɑːmfəl/ (UK) · CEFR B2 · Adjective

Source: https://englishreference.com/word/harmful
Updated: 2026-05-02

## Definition

causing damage or injury to someone or something. You use this to describe things that are bad for your health, the environment, or your success.

For teachers: causing or capable of causing physical, emotional, or environmental damage. Often used to describe substances, behaviors, or influences that have a negative impact on a subject.

## Examples

- Smoking is harmful to your health.
- The factory was fined for releasing harmful chemicals into the local river system.
- While some critics argue that the new policy is beneficial, others maintain that its long-term effects will be harmful to the country's economic stability.

## Usage notes

- Typically followed by the preposition 'to' when specifying the object being damaged.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.