Any one of numerous species of small aquatic Entomostraca belonging to the genera Cyclops, Daphnia, etc; -- so called because they swim with sudden leaps or starts.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). water flea. Retrieved September 24, 2026, from http://smartdefine.org/water_flea/definitions/2080895 |
| Chicago | Webster's. 2011. "water flea" http://smartdefine.org/water_flea/definitions/2080895 (accessed September 24, 2026). |
| Harvard | Webster's 2011, water flea, Smart Define, viewed 24 September, 2026, <http://smartdefine.org/water_flea/definitions/2080895>. |
| MLA | Webster's. "water flea" 28 May 2011. Web. 24 September 2026. <http://smartdefine.org/water_flea/definitions/2080895> |