- It's important to protect your skin from the harmful effects of the sun.
- Prolonged use of the drug is known to have harmful side-effects.
- The programme makers disagree that seeing violence on television has a harmful effect on children.
- Food must be heated to a high temperature to kill harmful bacteria.
- We've signed a treaty with neighbouring states to limit emissions of harmful gases.
adverb uk /ˈhɑːm.fəl.i/ us /ˈhɑːrm.fəl.i/
noun [ U ] uk /ˈhɑːm.fəl.nəs/ us /ˈhɑːrm.fəl.nəs/