hydrogenation
- n a chemical process that adds hydrogen atoms to an unsaturated oil
food producers use hydrogenation to keep fat from becoming rancid
hydrography
- n the science of the measurement and description and mapping of the surface waters of the earth with special reference to navigation
hydroiodic acid
- n an acid formed by aqueous solution of hydrogen iodide
hydrolith
- n a saltlike binary compound (CaH2) used as a reducing agent and source of hydrogen
hydrology
- n the branch of geology that studies water on the earth and in the atmosphere: its distribution and uses and conservation
hydrolysis
- n a chemical reaction in which water reacts with a compound to produce other compounds; involves the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion from the water
hydromancy
- n divination by water (as by patterns seen in the ebb and flow of the tides)
hydromantes brunus
- n similar to Shasta salamander; lives in cliff crevices and taluses
hydromantes shastae
- n primarily a cave dweller in the Mount Shasta area