he|li|um

he|li|um «HEE lee uhm», noun.

a very light, colorless, odorless gas that will not burn, much used in balloons and airships. Helium is an inert chemical element which occurs in small amounts in the air, in natural gas, in certain minerals, and as a product of many radioactive substances and processes. Helium, in the liquid state, is used as a refrigerant. It is also used in place of flammable gases in electric welding.

╂[< New Latin helium < Greek h sun (because its existence in the sun's atmosphere was inferred from the sun's spectrum)]