Absurd :: Absurd (a.) Contrary to reason or propriety; obviously and fiatly opposed to manifest truth; inconsistent with the plain dictates of common sense; logically contradictory; nonsensical; ridiculous; as, an absurd person, an absurd opinion; an absurd dream..
Surd :: Surd (a.) Involving surds; not capable of being expressed in rational numbers; radical; irrational; as, a surd expression or quantity; a surd number..
Surd :: Surd (a.) 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 :: Surd (n.) A quantity which can not be expressed by rational numbers; thus, �2 is a surd..
Surdal :: Surd (n.) A surd element of speech. See Surd, a., 4..