uranium

American

[yoo-rey-nee-uhm] / yʊˈreɪ ni əm /

noun

Chemistry.

a white, lustrous, radioactive, metallic element, occurring in pitchblende, and having compounds that are used in photography and in coloring glass. The 235 isotope is used in atomic and hydrogen bombs and as a fuel in nuclear reactors. U; 238.03; 92; 19.07.

uranium British

/ jʊˈreɪnɪəm /

noun

a radioactive silvery-white metallic element of the actinide series. It occurs in several minerals including pitchblende, carnotite, and autunite and is used chiefly as a source of nuclear energy by fission of the radioisotope uranium-235 . Symbol: U; atomic no: 92; atomic wt: 238.0289; half-life of most stable isotope, ²³⁸ U: 451 × 10 ⁹ years; valency: 2-6; relative density: 18.95 (approx.); melting pt: 1135°C; boiling pt: 4134°C

"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

uranium Scientific

/ y-rā′nē-əm /

A heavy, silvery-white, highly toxic, radioactive metallic element of the actinide series. It has 14 known isotopes, of which U 238 is the most naturally abundant, occurring in several minerals. Fissionable isotopes, especially U 235, are used in nuclear reactors and nuclear weapons. Atomic number 92; atomic weight 238.03; melting point 1,132°C; boiling point 3,818°C; specific gravity 18.95; valence 2, 3, 4, 5, 6.
See Periodic Table

uranium Cultural

A chemical element that is naturally radioactive. An isotope of uranium, uranium 235, is the main fuel for nuclear reactors and atomic bombs (see also atomic bomb). Its symbol is U. (See fission and chain reaction.)

Etymology

Origin of uranium

From New Latin, dating back to 1790–1800; Uranus, -ium

Compare meaning

How does uranium compare to similar and commonly confused words? Explore the most common comparisons:

plutonium vs. uranium

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The Modi government has been bullish on civilian nuclear power and wants to build more reactors, but it needs a steady supply of uranium to sustain the plan.

From BBC

Even enrichment to 1.5% purity would constitute half or more of the technical effort needed to achieve weapons-grade uranium.

From The Wall Street Journal

Iran insists on its right to enrich uranium but is floating proposals such as reducing enrichment.

From The Wall Street Journal

U.S. negotiators have pushed for Iran to dismantle several nuclear sites and transfer its remaining enriched uranium out of the country, the Wall Street Journal reported, citing officials.

From Barron's

About a third of that index consists of natural resources companies, including energy and commodities like uranium, copper, and gold.

From Barron's

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023