- 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
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.
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
- 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 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."