[ kuh-roh-nee-uh m ]
/ kəˈroʊ ni əm /

noun Astronomy.

a hypothetical element once thought to exist because certain spectral lines in the emission spectrum of the solar corona could not be identified by known elements. These lines were subsequently found to be emitted by certain highly ionized metals.

Origin of coronium

First recorded in 1885–90; coron(a) + -ium Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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