Selenium

noun

noun ·4 syllables ·Uncommon ·Advanced level

Definitions

Noun
  1. 1
    A nonmetallic chemical element (symbol Se) with an atomic number of 34, used mainly in glassmaking and pigments and as a semiconductor. uncountable, usually

    "Pluck almost any cell from your body and it will have a million or more selenium atoms in it."

  2. 2
    a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite) wordnet
  3. 3
    A single atom of this element. uncountable, usually

Synonyms

All synonyms
alabasterarsenicasphaltatomic number 34ddtmineral

Example

More examples

"Hydrogen, carbon, nitrogen, phosphorus, oxygen, sulfur and selenium are nonmetals."

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.

Related phrases

hydroselenic acidmetallic seleniumselenic acidselenious acidselenium cellselenium dioxideselenium eyeselenium hexafluorideselenium hydrideselenium oxideselenium sulfideselenium sulphide

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.