surd

Borrowed from Latin surdus (“deaf”); in mathematical sense, "deaf to reason", i.e. irrational.

• (Received Pronunciation) enPR: sûd, IPA^(key): /sɜːd/
• (US) enPR: sûrd, IPA^(key): /sɝd/
• Rhymes: -ɜː(r)d

surd (plural surds)

1. (arithmetic) An irrational number, especially one expressed using the √ symbol.
2. (linguistics) A voiceless consonant.

surd (comparative more surd, superlative most surd)

1. (obsolete) Lacking the sense of hearing; deaf.
   • 1670s, published 1716, Thomas Browne, Christian Morals, part 3, section 6:

     …how all Words fall to the Ground, spent upon such a surd and Earless Generation of Men, stupid unto all Instruction…

2. (obsolete) unheard
   • 1773, William Kenrick, A New Dictionary of the English Language, section 3, page 5:

     To this errour, of blending the ſurd and vocal modes of articulation together, may be added the too frequent uſe of compound articulations both vocal and ſurd.

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

   a surd expression or quantity; a surd number

4. (phonetics) unvoiced; voiceless

• RUDs, Ruds, UDRS, Urds, ruds

From Latin surdus, from Proto-Indo-European *swer- (“ringing, whistling”).

• IPA^(key): /surd/

surd m or n (feminine singular surdă, masculine plural surzi, feminine and neuter plural surde)

1. deaf

• asurzi
• surzi

• auzi
• mut
• orb