mysterium (suomeksi)

Määritelmät:

(lb, en, chemistry, alchemy, now, _, historical) Any of various unknown elements thought to make up existing forms of matter, or a substance seen as an elemental or pure form of something else.
(lb, en, astronomy, now, _, historical) The hypothetical source of a galactic radio emission at 1665 megahertz (later identified as due to hydroxyl radicals in interstellar space).