Meaning of SURD in English

SURD

I. ˈsərd adjective

Etymology: Latin surdus deaf, silent, stupid

Date: 1610

1. : lacking sense : irrational

surd conceits of scripture's sense — Thomas Jackson

2. : voiceless — used of speech sounds

II. noun

Date: 1557

1.

a. : an irrational root (as √3)

b. : irrational number

2. : a surd speech sound

Merriam-Webster's Collegiate English vocabulary.      Энциклопедический словарь английского языка Merriam Webster.