radian
/ˈɹeɪdiən/
"radian" is a 6-letter English headword indexed on PlainSpell.
The verdict
“radian” is uncommon English (frequency #82,702 among 21,470 “R” headwords), classed as a noun. The kind of spelling people second-guess.
- #82,702
- frequency rank, English
- 21,470
- “R” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - In the International System of Units, the derived unit of plane angle: the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle.
| Property | Value |
|---|---|
| Headword | radian |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈɹeɪdiən/ |
| Letters | 6 |
| Frequency rank | #82,702 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “radian” sits in English frequency
Rare enough to double-check
radian is uncommon English at frequency #82,702 among 21,470 “R” headwords, classed as anoun, transcribed /ˈɹeɪdiən/. Rarity is why readers land here mid-draft. Gloss: "In the International System of Units, the derived unit of plane angle: the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle.".
radian has no tracked misspelling variants, a sign its spelling follows regular English conventions. It is not paired with a close-neighbour confusable in our dataset, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.
Etymologically, the entry records: From radius + -an. The correct English form is radian, spelled R-A-D-I-A-N.
Definition
- 1In the International System of Units, the derived unit of plane angle: the angle subtended at the centre of a circle by an arc of its circumference equal in length to the radius of the circle.
Etymology
From radius + -an.
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 “radian”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is R-A-D-I-A-N - every other letter order is a misspelling in standard orthography.
- Say it as /ˈɹeɪdiən/ (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.