柯林斯词典helium /ˈhiːlɪəm/ 1. N-UNCOUNT Helium is a very light gas that is colourless and has no smell. 氦 返回 helium剑桥词典a chemical element that is a gas lighter than air , that will not burn and is used in balloons , airships , and some types of lights 氦 返回 helium