water bug wa·ter·bug uncommon noun 1. a true bug: large aquatic bug adapted to living in or on the surface of water Synonymswater bug 2. small light-brown cockroach brought to United States from Europe; a common household pest SynonymsGerman cockroachCroton bugcrotonbugwater bugBlattella germanica Related words Broader terms cockroachheteropterous insect Narrower terms giant water bugwater scorpionwater boatmanwater strider Parts Blattella WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
