Meaning

noun a symptom of rabies in humans consisting of an aversion to swallowing liquids

noun a morbid fear of water

noun an acute viral disease of the nervous system of warm-blooded animals (usually transmitted by the bite of a rabid animal); rabies is fatal if the virus reaches the brain

originFrom Middle English idroforbia (“hydrophobia”), from Latin hydrophobia, from Ancient Greek ὑδροφοβία (hudrophobía), from ὑδρο- (hudro-), combining form of ῠ̔́δωρ (hŭ́dōr, “water”), + φοβία (phobía, “phobia”). The word is analysable as hydro- + -phobia.

Etymology from Wiktionary, CC BY-SA 3.0