Also found in: Thesaurus, Medical, Encyclopedia.
n. Symbol H
A colorless, highly flammable element, that occurs as a diatomic molecule, H2, the lightest of all gases and the most abundant element in the universe, used in the production of synthetic ammonia and methanol, in petroleum refining, in the hydrogenation of organic materials, as a reducing atmosphere, in oxyhydrogen torches, in cryogenic research, and in rocket fuels. Atomic number 1; atomic weight 1.00794; melting point -259.1°C; boiling point -252.8°C; density at 0°C 0.08988 gram per liter; valence 1. See Periodic Table.
[French hydrogène : Greek hudro-, hydro- + French -gène, -gen.]
hy·drog′e·nous (-drōj′ə-nəs) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(Chemistry) of or containing hydrogen
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
hy•drog•e•nous(haɪˈdrɒdʒ ə nəs)
of or containing hydrogen.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.