a. - Not to be coerced; incapable of being compelled or forced.
a. - Not capable of being reduced to the form of a liquid by pressure; -- said of any gas above its critical point; -- also particularly of oxygen, hydrogen, nitrogen, and carbon monoxide, formerly regarded as incapable of liquefaction at any temperature or pressure.
a. - That can note be confined in, or excluded from, vessels, like ordinary fluids, gases, etc.; -- said of the imponderable fluids, heat, light, electricity, etc.