surd UK /sɜːd/US /sɝd/adjective 4noun 2forms 3 adjective4 •Involving surds, or irrational numbers; not capable of being expressed in rational numbers. •unvoiced; voiceless •(no longer used) unheardTo 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. — 1773 •(no longer used) Lacking the sense of hearing; deaf.…how all Words fall to the Ground, spent upon such a surd and Earless Generation of Men, stupid unto all Instruction… — 1716 noun2 •An irrational number, especially one expressed using the √ symbol. •A voiceless consonant. formssurds · more surd · most surd
