Meaning of SURD in English

SURD

I. adjective Etymology: Latin ~us deaf, silent, stupid Date: 1610 lacking sense ; irrational , voiceless , II. noun Date: 1557 1. an irrational root (as √3), irrational number , a ~ speech sound

Merriam Webster. Explanatory English dictionary Merriam Webster.      Толковый словарь английского языка Мерриам-Уэбстер.