# surd

- Phonetics. voiceless (opposed to sonant).
- Mathematics. (of a quantity) not capable of being expressed in rational numbers; irrational.

- Phonetics. a voiceless consonant (opposed to sonant).
- Mathematics. a surd quantity.

## Origin of surd

## 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 GeometryDavid Eugene Smith

For 'voiceless,' 'surd,' 'hard,' or 'tenuis' are sometimes used.

New Latin GrammarCharles E. Bennett

On the one hand Aristotle by his doctrine of matter admitted a surd into his system.

The rule of surd to surd and sonant to sonant is neglected in most of the factitious specimens of broken English.

Pennsylvania DutchS. S. Haldeman

The Sanskrit terms sonant and surd are, in a scientific point of view, the least exceptionable.

The English LanguageRobert Gordon Latham

## surd

- 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)

- of or relating to a surd

## Word Origin for surd

## Word Origin and History for surd

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."