Search Dictionary
Definition of plutonium

plutonium

/pluːˈtoʊ.ni.əm/
plu · to · ni · um
Adjective:plutonic
JUMP TO:

plutonium Lexical Profile

plutonium Game Scores & Validity

• noun

1

A dense, silvery, radioactive metallic element of the actinide series (atomic number 94, symbol Pu), produced artificially in nuclear reactors and used as a fuel source in nuclear power generation and space probes.

Example

"Deep-space robotic probes often rely on the steady heat generated by decaying plutonium to power their instruments far from the sun."

• Rhymes for plutonium

• Nearby Words

plushy
pluto
plutocracy
plutonium
ply
plyometric
plyometrics

Word Origin & Etymology

Coined in 1942 by American physicist Glenn T. Seaborg and his colleagues after the dwarf planet Pluto, following the naming of the preceding elements uranium (after Uranus) and neptunium (after Neptune).

Cite this Entry

Wordmom. (2026). Definition of Plutonium. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/plutonium
Built for writers, students, and competitive word game players, Wordmom combines an uncluttered English dictionary and thesaurus with fast, pattern-based word finders so you can verify definitions, synonyms, and high-scoring tile plays in one place.
Word Games & Solvers
Word FinderScrabble Word FinderWords With Friends CheatWordle SolverAnagram Solver
Dictionary & Reference
DictionarySynonymsAntonymsWords
Community
Contact UsEditorial PolicyPrivacy PolicyTerms and Conditions
© 2016–2026 Wordmom Network. All rights reserved. Made with for word lovers everywhere.
Disclaimer: SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A. and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. Words With Friends® is a registered trademark of Zynga Inc. Wordle® is a registered trademark of The New York Times Company. Other referenced game titles and tournament lexicon codes (including NASPA NWL and WESPA/HarperCollins CSW) are trademarks of their respective owners. Wordmom is an independent reference utility for educational and entertainment purposes and is not affiliated with, sponsored by, or endorsed by Hasbro, Mattel, Spear, Zynga, The New York Times Company, NASPA, WESPA, or HarperCollins Publishers. All game names are referenced strictly under nominative fair use to indicate compatibility.