·adj Unheard.
II. Surd ·adj Net having the sense of hearing; deaf.
III. Surd ·noun A surd element of speech. ·see Surd, ·adj, 4.
IV. Surd ·noun A quantity which can not be expressed by rational numbers; thus, Ã2 is a surd.
V. Surd ·adj Involving surds; not capable of being expressed in rational numbers; radical; irrational; as, a surd expression or quantity; a surd number.
VI. Surd ·adj Uttered, as an element of speech, without tone, or proper vocal sound; voiceless; unintonated; nonvocal; atonic; whispered; aspirated; sharp; hard, as f, p, s, ·etc.;
— opposed to sonant. ·see Guide to Pronunciation, //169, 179, 180.