/ Dictionary / Index W water bug: Meaning and Definition of Find definitions for: wa'ter bug" Pronunciation: [key] any of various aquatic bugs, as of the family Belostomatidae (loosely) a large cockroach, esp. the American cockroach. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. water buffalo Waterbury Related Content Daily Word Quiz: cetacean Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language