If you describe someone or something as harmless, you mean that they are not important and therefore unlikely to annoy other people or cause trouble. He seemed harmless enough I would not want to deny them a harmless pleasure. + harmlessly harm·less·ly It started harmlessly enough, with a statement from the Secretary of State for Social Security
not threatening to life or health; not malignant; "a benign tumor is usually harmless" not causing or capable of causing harm; "harmless bacteria"; "rendered the bomb harmless" unlikely to harm or disturb anyone; "harmless old man" not producing any toxic effects
Something that is harmless does not have any bad effects, especially on people's health. Industry has been working at developing harmless substitutes for these gases This experiment was harmless to the animals. = safe harmful + harmlessly harm·less·ly Another missile exploded harmlessly outside the town