hy‧dro‧gen /ˈhaɪdrədʒən/ noun [uncountable]
[Date: 1700-1800; Language: French; Origin: hydrogène, from hydro- ( ⇒ hydro-) + -gène 'producing'; because it produces water when it is burned]
a colourless gas that is the lightest of all gases, forms water when it combines with oxygen, and is used to produce ammonia and other chemicals. It is a chemical element: symbol H

[TahlilGaran] Dictionary of Contemporary English ▲