radian
/ˈɹeɪdiən/noun
radian is a noun meaning “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…” (English Wiktionary, September 2026). It is spelled R-A-D-I-A-N, and it appears about once in every 8 million words in written English (wordfreq, 2021 data). The plural of radian is radians.
What does radian mean?
noun
- 1
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.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How do you pronounce radian?
- /ˈɹeɪdiən/
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-radian.wav, Wikimedia Commons (author and licence on each file's page).
Forms of radian
- radians plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
How common is radian?
Radian appears about once in every 8 million words in written English, the 82,325th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you abbreviate radian?
Wiktionary records one abbreviation of radian: rad..
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Radian in Spanish, French, German and Portuguese
In the sense unit:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does radian come from?
From radius + -an.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).