variants or less commonly blood worm
plural bloodworms also blood worms
: any of various pink to red worms: such as
a
: any of a genus (Glycera) of bristle worms that live in shallow marine waters or tidal flats and that are often used as bait
b
: the bright red aquatic larva of a midge fly and especially a chironomid that is commonly used as food for aquarium fish
c
: any of several strongyle worms (such as Strongylus vulgaris) that are intestinal parasites of horses and that typically migrate to the liver, pancreas, or blood vessels

Examples of bloodworm in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
As water temperatures plunge and ice covers the surface, the bluegill buffet shifts to bloodworms, freshwater shrimp and scuds, and even tiny zooplankton. Outdoor Life, 27 Jan. 2020 Maine’s catch of bloodworms has dropped from more than 600,000 pounds in 2004 to less than half that last year. Washington Post, 27 Apr. 2017 An October study in the journal Fish and Fisheries said bloodworms are the most valuable marine worm species on the retail bait market, and sandworms aren’t far behind. Patrick Whittle, The Seattle Times, 27 Apr. 2017 The price for bloodworms at the dock has more than doubled since 2001, to nearly $16 per pound, and that cost is eventually borne by consumers. Washington Post, 27 Apr. 2017 These baits are a good imitation of a bloodworm, which is a common food source for a variety of fish in most waters. Terry Wickstrom, The Denver Post, 14 Mar. 2017

Word History

First Known Use

1736, in the meaning defined above

Time Traveler
The first known use of bloodworm was in 1736

Browse Nearby Words

Cite this Entry

“Bloodworm.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/bloodworm. Accessed 2 Aug. 2026.

Medical Definition

variants also blood worm
: any of several comparatively large bloodsucking nematode worms of the genus Strongylus that are parasitic in the large intestine of horses and have larvae which wander in the viscera and sometimes lodge in the intestinal blood vessels causing colic or more rarely a fatal aneurysm

called also palisade worm, red worm

More from Merriam-Webster on bloodworm

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!