Any one of numerous species of aquatic beetles belonging to Dytiscus and allied genera of the family Dytiscidae, and to various genera of the family Hydrophilidae. These beetles swim with great agility, the fringed hind legs acting together like oars.
WATER BEETLE
Meaning of WATER BEETLE in English
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012