surd

[surd]

SEE MORE SYNONYMS FOR surd ON THESAURUS.COM

adjective

Phonetics. voiceless (opposed to sonant).

Mathematics. (of a quantity) not capable of being expressed in rational numbers; irrational.

noun

Phonetics. a voiceless consonant (opposed to sonant).

Mathematics. a surd quantity.

Origin of surd

First recorded in 1545–55, surd is from the Latin word surdus dull-sounding, mute, deaf

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for surd

dumb, inarticulate, mum, mute, silent, speechless, aphonic

Examples from the Web for surd

Historical Examples of surd

Of course this gives a number, but this number may be a surd, like √2.
The Teaching of Geometry
David Eugene Smith
For 'voiceless,' 'surd,' 'hard,' or 'tenuis' are sometimes used.
New Latin Grammar
Charles E. Bennett
On the one hand Aristotle by his doctrine of matter admitted a surd into his system.
Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 8
Various
The rule of surd to surd and sonant to sonant is neglected in most of the factitious specimens of broken English.
Pennsylvania Dutch
S. S. Haldeman
The Sanskrit terms sonant and surd are, in a scientific point of view, the least exceptionable.
The English Language
Robert Gordon Latham

British Dictionary definitions for surd

surd

noun

maths an expression containing one or more irrational roots of numbers, such as 2√3 + 3√2 + 6

phonetics a voiceless consonant, such as (t)

adjective

of or relating to a surd

Word Origin for surd

C16: from Latin surdus muffled

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for surd

adj.

1550s, "irrational" (of numbers), from Latin surdus "unheard, silent, dull," possibly related to susurrus "a muttering, whispering" (see susurration). The mathematical sense is from the use of Latin surdus to translate Arabic (jadhr) asamm "deaf (root)," itself a loan-translation of Greek alogos, literally "speechless, without reason" (Euclid book x, Def.). In French, sourd remains the principal word for "deaf."