Definitions

1. noun

A number that cannot be expressed as a finite decimal, especially a square root of a negative number.

“The mathematician studied irrational numbers, including surds, to better understand their properties.”

2. adjective

Relating to a number that cannot be expressed as a finite decimal.

“The surd nature of the square root made it difficult to calculate accurately.”

3. verb

To make a sound, especially a harsh or guttural one.

“The crowd surged forward, surding loudly as they waited for the concert to begin.”