Meaning of SURD in English

SURD

I. ˈsərd, ˈsə̄d, ˈsəid adjective

Etymology: Latin surdus dull-sounding, silent, deaf; akin to Latin susurrus hum, murmur — more at swarm

1. : lacking sense : lacking reason or rationale : insensate , irrational

the surd mystery and the strange forces of existence — D.C.Williams

2. : voiceless — used of speech sounds; opposed to sonant

II. noun

( -s )

: one that is surd: as

a. : an irrational radical with rational radicand

√3 and √ 2/5 are surds

b. : a surd speech sound

c. : an unknown or irrational quality

the uncharted surd at the heart of European politics — William Barrett

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.