1550s, "irrational" (of numbers), from Latin surdus "deaf, unheard, silent, dull; willfully deaf, inattentive," 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 apparently a loan-translation of Greek alogos, literally "speechless, without reason" (Euclid book x, Def.). In French, sourd remains the principal word for "deaf." As a noun from 1540s. Related: Surdity.
权威例句
1. The square root of 5 is a surd.
5的平方根是不尽根.
2. Example 1 : Solve the following quadratic equations, leave the answers in surd form.
例 1: 解下列的二次方程, 如果需要,以根式表示.
3. This ab - surd situation occurs because laws are made , en - forced, and reported on by lawyers.