Ekasilicon n. : The name of a hypothetical element predicted and afterwards discovered and named germanium; -- so called because it was a missing analogue of the silicon group. See Germanium, and cf. Ekabor.

Example:


Taxonomy
elements, predictions, atomic mass, Dmitri Mendeleev, the periodic table, density, gases, ether, Mendeleev's predicted elements, lighter, oxide, cm³, Ekasilicon, scandium, free encyclopedia, atomic elements, ekaboron, gallium.

Defination from the web:
Ekasilicon and germanium. 2 1871 predictions. 3 Later predictions of elements coronium and ether. 4 Notes and references. 5 Further reading ... elements lighter than the rare earth elements, ekaboron (Eb), ekaaluminium (Ea), ekamanganese (Em), and ekasilicon (Es), proved to be good ...