# thorium

> English word · Noun · IPA /ˈθɔːɹiəm/ · frequency rank #37,733

## Definitions
1. A chemical element (symbol Th) with atomic number 90. A weakly radioactive, malleable, moderately hard silvery metal that tarnishes black when exposed to air.

## Etymology
From Thor + -ium.

## Common misspellings (10)
`htorium`, `thhorium`, `thoirum`, `thorimu`, `thoriumm`, `thorrium`, `thoruim`, `throium`, `tohrium`, `tthorium`

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