indicating or denoting water, liquid, or fluid: hydrolysis, hydrodynamics
2.
indicating the presence of hydrogen in a chemical compound: hydrochloric acid
3.
indicating a hydroid: hydrozoan
Word Origin
from Greek hudōr water
Word Origin and History for hydro-
before vowels hydr-, word-forming element meaning "water," from Greek hydro-, comb. form of hydor "water" (see water (n.1)). Also sometimes a comb. form of hydrogen.
hydro- in Medicine
hydro- or hydr- pref.
Water; liquid: hydrocephalus.
Hydrogen: hydrochloride.
hydro- in Science
hydro- A prefix that means: "water" (as in hydroelectric) or "hydrogen," (as in hydrochloride).