n. [ Tetra- + Gr. &unr_;, &unr_;, tooth. ] (Zool.) Any one of numerous species of plectognath fishes belonging to Tetrodon and allied genera. Each jaw is furnished with two large, thick, beaklike, bony teeth. [ Written also tetradon. ] [ 1913 Webster ]

☞ The skin is usually spinous, and the belly is capable of being greatly distended by air or water. It includes the swellfish, puffer (a), and similar species. [ 1913 Webster ]

a. (Zool.) Of or pertaining to the tetrodons. -- n. A tetrodon. [ Written also tetradont, and tetraodont. ] [ 1913 Webster ]

n. [ Tetra- + benzol. ] (Chem.) A hypothetical hydrocarbon, C4H4, analogous to benzene; -- so called from the four carbon atoms in the molecule. [ 1913 Webster ]

Tetrol phenol, furfuran. [ Obs. ] [ 1913 Webster ]

a. (Chem.) Of, pertaining to, or designating, an acid, C3H3.CO2H, of the acetylene series, homologous with propiolic acid, obtained as a white crystalline substance. [ 1913 Webster ]

n. [ Tetra- + -ose. ] (Chem.) A monosaccharide derived from a certain alcohol. [ Webster 1913 Suppl. ]

n. [ Tetra- + oxide. ] (Chem.) An oxide having four atoms of oxygen in the molecule; a quadroxide; as, osmium tetroxide, OsO4. [ 1913 Webster ]