The word "etherion" is not commonly used in English, and there is no clear IPA phonetic transcription for it. It is possible that the word refers to the hypothetical substance "ether," which was once believed by some to permeate empty space and serve as the medium for light and electromagnetic waves. However, the spelling and pronunciation of "ether" varies depending on context and usage, so it is unclear how the spelling of "etherion" would relate.
A supposed new element, a gas of extreme tenuity existing in the atmosphere and perhaps throughout space; said by some to be only watery vapor.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.