Tetrachord :: Tetrachord (n.) A scale series of four sounds, of which the extremes, or first and last, constituted a fourth. These extremes were immutable; the two middle sounds were changeable..
Tetrachotomous :: Tetrachotomous (a.) Having a division by fours; separated into four parts or series, or into series of fours..
Tetracid :: Tetracid (a.) Capable of neutralizing four molecules of a monobasic acid; having four hydrogen atoms capable of replacement ba acids or acid atoms; -- said of certain bases; thus, erythrine, C4H6(OH)4, is a tetracid alcohol..
Tetracoccous :: Tetracoccous (a.) Having four cocci, or carpels..
Tetracolon :: Tetracolon (n.) A stanza or division in lyric poetry, consisting of four verses or lines..
Tetractinellid :: Tetractinellid (n.) Any species of sponge of the division Tetractinellida. Also used adjectively.
Tetractinellida :: Tetractinellida (n. pl.) A division of Spongiae in which the spicules are siliceous and have four branches diverging at right angles. Called also Tetractinellinae.