thallium
/ˈθæliəm/
"thallium" is a 8-letter English headword indexed on PlainSpell.
The verdict
“thallium” is uncommon English (frequency #70,326 among 27,828 “T” headwords), classed as a noun. The kind of spelling people second-guess.
- #70,326
- frequency rank, English
- 27,828
- “T” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A metallic chemical element (symbol Tl) with atomic number 81: a gray post-transition metal that discolors when exposed to air.
| Property | Value |
|---|---|
| Headword | thallium |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈθæliəm/ |
| Letters | 8 |
| Frequency rank | #70,326 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “thallium” sits in English frequency
Rare enough to double-check
thallium is uncommon English at frequency #70,326 among 27,828 “T” headwords, classed as anoun, transcribed /ˈθæliəm/. Rarity is why readers land here mid-draft. 2 senses are on record.
The misspelling generator found no plausible variants for thallium, which points to an orthography that plays by predictable English rules. This entry stands alone in our confusable dataset, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.
Etymologically, the entry records: Coined based on Ancient Greek θαλλός (thallós, “green branch”) (after the color of the radiation spectra), + -ium. The correct English form is thallium, spelled T-H-A-L-L-I-U-M.
Definition
- 1A metallic chemical element (symbol Tl) with atomic number 81: a gray post-transition metal that discolors when exposed to air.
- 2A single atom of this element.
Etymology
Coined based on Ancient Greek θαλλός (thallós, “green branch”) (after the color of the radiation spectra), + -ium.
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Using “thallium”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is T-H-A-L-L-I-U-M - every other letter order is a misspelling in standard orthography.
- Say it as /ˈθæliəm/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Browse more English words and confusable pairs in the same reference. English words
Other uncommon English words near this rank
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.