← BackshareGuessunharmful/ʌnˈhɑːrmfəl/adjectiveNot causing or likely to cause harm; safe.They assured us the chemical was unharmful in small amounts.Her joke was meant to be unharmful, but some took offense.The insect is unharmful to humans and plants.SynonymssafeinnocuousbenignAntonymsdangerousharmful