Defn: To combine with hydrogen; to treat with, or subject to the action of, hydrogen; to reduce; — contrasted with oxidize.

HYDROGENOUS
Hy*drog"e*nous, a.

Defn: Of or pertaining to hydrogen; containing hydrogen.

HYDROGNOSY
Hy*drog"no*sy, n. Etym: [Hydro-, 1 + Gr.

Defn: A treatise upon, or a history and description of, the water of the earth.

HYDROGODE
Hy"drog*ode, n. Etym: [Hydrogen + Gr. (Elec.)

Defn: The negative pole or cathode. [R.]

HYDROGRAPHER
Hy*drog"ra*pher, n.

Defn: One skilled in the hydrography; one who surveys, or draws maps or charts of, the sea, lakes, or other waters, with the adjacent shores; one who describes the sea or other waters. Boyle.

HYDROGRAPHIC; HYDROGRAPHICAL
Hy`dro*graph"ic, Hy`dro*graph"ic*al, a.