Main Entry: hy·dro·gen

Pronunciation: \ˈhī-drə-jən, -dər-\

Function: noun

Etymology: French hydrogène, from hydr- + -gène -gen; from the fact that water is generated by its combustion

Date: 1788

: a nonmetallic element that is the simplest and lightest of the elements, is normally a colorless odorless highly flammable diatomic gas, and is used especially in synthesis — see element table — compare deuterium, tritium

— hy·drog·e·nous \hī-ˈdrä-jə-nəs\ adjective