follow Dictionary.com

Yours, Etc.: Origins and Uses of 8 Sign-Offs

selenium

[si-lee-nee-uh m] /sɪˈli ni əm/
noun, Chemistry
1.
a nonmetallic element chemically resembling sulfur and tellurium, occurring in several allotropic forms, as crystalline and amorphous, and having an electrical resistance that varies under the influence of light. Symbol: Se; atomic weight: 78.96; atomic number: 34; specific gravity: (gray) 4.80 at 25°C, (red) 4.50 at 25°C.
Origin
< Neo-Latin (1818) < Greek selḗn(ē) moon + Neo-Latin -ium -ium; named in allusion to its similarity to tellurium
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples from the web for selenium
  • The list includes several vitamins and inorganic minerals as common as salt and as rare as selenium or iodine.
  • Their cores contain paired clusters of atoms such as cadmium and selenium that combine to create a semiconductor.
  • She tosses in multivitamins and the mineral selenium, plus a pair of preparations to lower her cholesterol.
  • selenium is a trace mineral essential to good health.
  • The major dietary source of selenium is plant foods.
  • We are proposing draft revised water quality criteria for selenium.
British Dictionary definitions for selenium

selenium

/sɪˈliːnɪəm/
noun
1.
a nonmetallic element that exists in several allotropic forms. It occurs free in volcanic areas and in sulphide ores, esp pyrite. The common form is a grey crystalline solid that is photoconductive, photovoltaic, and semiconducting: used in photocells, solar cells, and in xerography. Symbol: Se; atomic no: 34; atomic wt: 78.96; valency: –2, 4, or 6; relative density: 4.79 (grey); melting pt: 221°C (grey); boiling pt: 685°C (grey)
Word Origin
C19: from New Latin, from Greek selēnē moon; named by analogy to tellurium (from Latin tellus earth)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for selenium
n.

element name, Modern Latin, from Greek selene "moon" (see Selene). Named by Berzelius (1818), on analogy of tellurium, with which it had been at first confused, and which was named for the earth. Despite the -ium ending it is not a metal and a more appropriate name selenion has been proposed.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
selenium in Medicine

selenium se·le·ni·um (sĭ-lē'nē-əm)
n.
Symbol Se
A nonmetallic element, with red, black, and gray allotropic forms, resembling sulfur and obtained primarily as a byproduct of electrolytic copper refining. Atomic number 34; atomic weight 78.96; melting point (of gray selenium) 221°C; boiling point (gray) 684.9°C; specific gravity (gray) 4.79; (black) 4.28; valence 2, 4, or 6.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
selenium in Science
selenium
  (sĭ-lē'nē-əm)   
Symbol Se
A nonmetallic element that occurs in a gray crystalline form, as a red powder, or as a black glassy material. It is highly photosensitive and can be used to convert light into electricity. Its ability to conduct electricity also increases with higher exposure to light. For these reasons selenium is used in photocopying technology, photography, and solar cells. Atomic number 34; atomic weight 78.96; melting point 217°C; boiling point 684.9°C; specific gravity (gray) 4.79; (red) 4.5; (black) 4.28; valence 2, 4, or 6. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Word Value for selenium

10
14
Scrabble Words With Friends

Nearby words for selenium