# plutonium

> English word · Noun · IPA /pluːˈtoʊniəm/ · frequency rank #21,318

## Definitions
1. The transuranic chemical element with atomic number 94 and symbol Pu: a silvery-gray fissile radioactive actinide metal that tarnishes when exposed to air.
2. Alternative form of ploutonion.

## Etymology
After Pluto (dwarf planet) + -n- + -ium. More in Wikipedia at plutonium § History.

## Common misspellings (13)
`lputonium`, `pllutonium`, `pltuonium`, `pluotnium`, `plutnoium`, `plutoinum`, `plutonimu`, `plutoniumm`, `plutonnium`, `plutonuim`, `pluttonium`, `pplutonium`, `pultonium`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/plutonium