Answer
The vast majority of medical terms have Greek and Latin roots, prefixes, and suffixes. This makes it easy as it forms a sort of standard that matches vocabulary to its designated meaning.
Work Step by Step
For example, "hydro" means water, such as in hydrosphere and anhydrous. "Phobia" means fear, such as in acrophobia and gamophobia. But together, hydrophobia means the fear, or aversion, of water.