harmful

Everyday

Harmful means causing harm: hurting people, animals, plants or things, or making them ill. tree →

In the lessons

In safety and health, harmful things include poisons, cleaning products, smoking, too much sun and some plants and berries; labels say «harmful if swallowed». In science, pollution and plastic are harmful to wildlife and the environment. Online, some websites and messages are harmful, so children should tell an adult. In feelings, harmful words can hurt as much as hitting. Opposite: harmless.

Examples

• Bleach is harmful if swallowed. tree →
• Smoking is harmful to your health. tree →
• Plastic in the sea is harmful to turtles. tree →
• Too much sun is harmful to your skin. tree →
• Some berries are harmful, so never eat wild ones. tree →
• Tell an adult if you see something harmful online. tree →
• Rumours can be harmful to people. tree →

Note

Spelt with one l: harmful (not «harmfull»). Opposite «harmless» (causing no harm). Say «harmful to» someone. «Harm» is the noun and verb: do harm, harm someone. A label saying «harmful» means keep it away from children.