platinum

[ plat-n-uhm, plat-nuhm ]
/ ˈplæt n əm, ˈplæt nəm /

noun

Chemistry. a heavy, grayish-white, highly malleable and ductile metallic element, resistant to most chemicals, practically unoxidizable except in the presence of bases, and fusible only at extremely high temperatures: used for making chemical and scientific apparatus, as a catalyst in the oxidation of ammonia to nitric acid, and in jewelry. Symbol: Pt; atomic weight: 195.09; atomic number: 78; specific gravity: 21.5 at 20°C.
a light, metallic gray with very slight bluish tinge when compared with silver.

adjective

made of platinum.
(of an audio recording) having sold a minimum of one million copies.

QUIZZES

GEE WHILLIKERS! WAIT TILL YOU SEE THIS WORD OF THE DAY QUIZ!

Do you remember all the words from last week, September 21–27, 2020? Then this quiz should be butyraceous.
Question 1 of 7
What does “yare” mean?

Origin of platinum

1805–15; <New Latin, alteration of earlier platina <Spanish; see platina
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for platinum

British Dictionary definitions for platinum

platinum
/ (ˈplætɪnəm) /

noun

a ductile malleable silvery-white metallic element, very resistant to heat and chemicals. It occurs free and in association with other platinum metals, esp in osmiridium: used in jewellery, laboratory apparatus, electrical contacts, dentistry, electroplating, and as a catalyst. Symbol: Pt; atomic no: 78; atomic wt: 195.08; valency: 1–4; relative density: 21.45; melting pt: 1769°C; boiling pt: 3827±100°C
  1. a medium to light grey colour
  2. (as adjective)a platinum carpet

Word Origin for platinum

C19: New Latin, from platina, on the model of other metals with the suffix -um
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

Medical definitions for platinum

platinum
[ plătn-əm ]

n. Symbol Pt

A ductile malleable metallic element usually occurring mixed with other metals such as iridium, osmium, or nickel and used as a catalyst and in dentistry. Atomic number 78.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for platinum

platinum
[ plătn-əm ]

Pt

A soft, ductile, malleable, silver-white metallic element that usually occurs with osmium, iridium, palladium, or nickel. It has a high melting point and does not corrode in air. Platinum is used as a catalyst and in making jewelry, electrical contacts, and dental crowns. Atomic number 78; atomic weight 195.08; melting point 1,772°C; boiling point 3,827°C; specific gravity 21.45; valence 2, 3, 4. See Periodic Table.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.