- Math. irrational
- Phonet. voiceless ()
Origin: L surdus, deaf, dull, mute: used to transl. Gr alogos, irrational, lit., without reason
- Math. an irrational number or quantity; specif., a root which can be expressed only approximately: is a surd
- Phonet. a voiceless sound
Used by arrangement with John Wiley & Sons, Inc.
- Mathematics An irrational number, such as √2.
- Linguistics A voiceless sound in speech.
Origin: Medieval Latin surdus, speechless, surd (translation of Arabic (jaḏr) ’aṣamm, deaf (root), surd, translation of Greek alogos, speechless, surd), from Latin.