backswimmer

[bak-swim-er]

noun

any of numerous predaceous aquatic hemipterous insects, of the family Notonectidae, that swim on their backs, and may inflict a painful bite if handled.

Origin of backswimmer

First recorded in 1860–65; back¹ + swimmer

Also called boat bug.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018