SURD

unvoiced, voiceless, surd, hard

(adjective) produced without vibration of the vocal cords; “unvoiced consonants such as ‘p’ and ‘k’ and ‘s’”

surd, voiceless consonant

(noun) a consonant produced without sound from the vocal cords

Source: WordNet® 3.1

Etymology

Noun

surd (plural surds)

(arithmetic) An irrational number, especially one expressed using the √ symbol.

(linguistics) A voiceless consonant.

Adjective

surd (comparative more surd, superlative most surd)

(obsolete) Lacking the sense of hearing; deaf.

(obsolete) unheard

(math) Involving surds, or irrational numbers; not capable of being expressed in rational numbers.

(phonetics) unvoiced; voiceless

Anagrams

• RUDs, Ruds, UDRS, Urds, ruds

Source: Wiktionary

Surd, a. Etym: [L. surdus deaf (whence the meaning, deaf to reason, irrational), perhaps akin to E. swart. Cf. Sordine.]

1. Net having the sense of hearing; deaf. [Obs.] "A surd . . . generation." Sir T. Browne.

2. Unheard. [Obs.] Kenrick.

3. (Math.)

Definition: Involving surds; not capable of being expressed in rational numbers; radical; irrational; as, a surd expression or quantity; a surd number.

4. (Phonetics)

Definition: 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.

Surd, n. (Math.)

1. A quantity which can not be expressed by rational numbers; thus, *2 is a surd.

2. (Phon.)

Definition: A surd element of speech. See Surd, a., 4.

Source: Webster’s Unabridged Dictionary 1913 Edition