The Collaborative International Dictionary
Hydro- \Hy"dro-\, Hydr- \Hy"dr-\
A combining form from Gr. ?, ?, water (see Hydra).
(Chem.) A combining form of hydrogen, indicating hydrogen as an ingredient, as hydrochloric; or a reduction product obtained by hydrogen, as hydroquinone.
Douglas Harper's Etymology Dictionary
pre. 1 water 2 (context chemistry English) hydrogen 3 (context mineralogy English) a hydrous compound 4 (context zoology English) Hydrozoa
Usage examples of "hydro-".
Instantly, the control room filled with holographic images, a crowd of milling beings, mimicking various kinds of oxy-, hydro-, and machine life.