Entomology definition of Hydro September 9, 2014 Raj Entomology Dictionary 0 Please Like Us!!! DesiGoogly.com > Education News > Entomology Dictionary > Entomology definition of Hydro Entomology definition of Hydro: relating to water: a combining form used as a prefix. Entomology Hydro definitionHydro Entomology explanationHydro Entomology meaningReviews & Comments