Surd
adj, noun ·Common ·High school level
Definitions
- 1 An irrational number, especially one expressed using the √ symbol.
- 2 a consonant produced without sound from the vocal cords wordnet
- 3 A voiceless consonant.
- 1 Lacking the sense of hearing; deaf. obsolete
"…how all Words fall to the Ground, spent upon such a surd and Earless Generation of Men, stupid unto all Instruction…"
- 2 unheard obsolete
"To this errour, of blending the ſurd and vocal modes of articulation together, may be added the too frequent uſe of compound articulations both vocal and ſurd."
- 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
- 1 produced without vibration of the vocal cords wordnet
Antonyms
All antonymsExample
More examples"…how all Words fall to the Ground, spent upon such a surd and Earless Generation of Men, stupid unto all Instruction…"
Etymology
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.
Related phrases
More for "surd"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.