[fos-fer, -fawr]


any of a number of substances that exhibit luminescence when struck by light of certain wavelengths, as by ultraviolet.
Literary. a phosphorescent substance.


Archaic. phosphorescent.

Origin of phosphor

1625–35; < French phosphore < Latin Phōsphorus Phosphor


[fos-fer, -fawr]


the morning star, especially Venus.
Also Phos·phore [fos-fawr, -fohr] /ˈfɒs fɔr, -foʊr/, Phosphorus.

Origin of Phosphor

1625–35; < Latin Phōsphorus < Greek Phōsphóros the morning star, literally, the light-bringing one, equivalent to phôs light + -phoros bringing; see -phorous


variant of phosphoro- before a vowel: phosphorate. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for phosphor

Lucifer, Phosphor, Phosphorus, Venus, daystar

Examples from the Web for phosphor

Historical Examples of phosphor

British Dictionary definitions for phosphor



a substance, such as the coating on a cathode-ray tube, capable of emitting light when irradiated with particles or electromagnetic radiation

Word Origin for phosphor

C17: from French, ultimately from Greek phōsphoros phosphorus
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

Word Origin and History for phosphor

"morning star," 1630s, from Latin phosphorus "the morning star" (see phosphorus). Meaning "anything phosphorescent" is from 1705.

Online Etymology Dictionary, © 2010 Douglas Harper

phosphor in Medicine



Variant ofphosphoro-
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

phosphor in Science



Any of various substances that can emit light after absorbing some form of radiation. Television screens and fluorescent lamp tubes are coated on the inside with phosphors. See Note at cathode-ray tube.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.