- any long, slender worm of the phylum Nematomorpha, developing parasitically on insects and crustaceans, and free-living as adults in streams and ponds.
Origin of horsehair worm
First recorded in 1745–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- another name for hairworm (def. 2)