surd
/sɝd/noun, adjective
surd is spelled S-U-R-D: 4 letters. It appears about once in every 35 million words in written English, the 180,281st most frequent word form (wordfreq, 2021 data). As a noun, surd means “An irrational number, especially one expressed using the √ symbol” (English Wiktionary, September 2026). The plural of surd is surds.
How many letters and syllables are in surd?
| Letters | 4: S-U-R-D |
|---|---|
| In writing | about once in every 35 million words; the 180,281st most frequent word form |
| Wrong spellings searched | none measured in search |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is surd?
Surd appears about once in every 35 million words in written English, the 180,281st 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 pronounce surd?
- UK /sɜːd/
- US /sɝd/
- /sʌɹd/
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Vealhurl-surd.wav, Wikimedia Commons (author and licence on each file's page).
What rhymes with surd?
The 12 most written words on PlainSpell end in the same sounds as surd from its last stressed vowel (/ɜɹd/):
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of surd
- surds plural
- more surd comparative
- most surd superlative
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does surd mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
An irrational number, especially one expressed using the √ symbol.
- 2
A voiceless consonant.
adjective
- 1
obsoleteLacking the sense of hearing; deaf.
…how all Words fall to the Ground, spent upon such a surd and Earless Generation of Men, stupid unto all Instruction…
- 2
obsoleteunheard
- 3
Involving surds, or irrational numbers; not capable of being expressed in rational numbers.
a surd expression or quantity; a surd number
- 4
unvoiced; voiceless
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Where does surd come from?
First attested in the mid 16th century from Latin surdus (“deaf, mute”), used in mathematics for “irrational,” reflecting ἄλογος (álogos, “irrational, speechless”) as found in Euclid, apparently transmitted via Arabic جِذْر أَصَمّ (jiḏr ʔaṣamm, “deaf root”). The phonetic sense, “voiceless,” emerged in the 18th century. Doublet of surdo.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).