/ Dictionary / Index H Hydrus: Meaning and Definition of Find definitions for: Hy•drus Pronunciation: (hī'drus), [key] — gen. -dri the Water Snake, a southern constellation between Eridanus and Octans. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hydrus (Thesaurus) hydrozoan hyena Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language