selenium
/sɪˈliːni.əm/ noun
Forms seleniums
- noun A nonmetallic chemical element (symbol Se) with an atomic number of 34, used mainly in glassmaking and pigments and as a semiconductor.
- noun An atom of this element.
Synonyms
Etymology
From French sélénium, the name coined by Swedish chemist Jöns Jacob Berzelius in 1818 from Ancient Greek σελήνη (selḗnē, “moon”) in reference to original confusion with the similar element tellurium.
Webster’s 1913
- noun A nonmetallic element of the sulphur group, and analogous to sulphur in its compounds. It is found in small quantities with sulphur and some sulphur ores, and obtained in the free state as a dark reddish powder or crystalline mass, or as a dark metallic-looking substance. It exhibits under the action of light a remarkable variation in electric conductivity, and is used in certain electric apparatus. Symbol Se. Atomic weight 78.9.
Etymology [NL., from Gr. tellurium (from L. tellus the earth), being, as it were, a companion to it.]
Sources: Wiktionary · WordNet 3.0 · Webster’s 1913 — from the Wiktionary entry “selenium”, CC BY-SA 4.0. Details