Merriam-Webster Collegiate Dictionary - taurine

 I. adjective  Etymology: Latin taurinus, from taurus bull; akin to Greek tauros bull, Middle Irish tarb  Date: 1613 of or relating to a bull ; bovine  II. noun  Etymology: International Scientific Vocabulary, from Latin taurus; from its having been discovered in ox bile  Date: 1845 a crystalline acid C2H7NO3S that is synthesized in the body from cysteine and methionine, is similar to amino acids but is not a component of proteins, and is involved in various physiological functions (as bile acid conjugation and cell membrane stabilization)