poly·​chaete ˈpä-lē-ˌkēt How to pronounce polychaete (audio)
: any of a class (Polychaeta) of chiefly marine annelid worms (such as clam worms) usually with paired segmental appendages, separate sexes, and a free-swimming trochophore larva
polychaete adjective

Example Sentences

Recent Examples on the Web In all likelihood, they were deposited by small, soft-bodied worms—probably an annelid worm like a polychaete—who could have navigated those tight spaces. Jennifer Ouellette, Ars Technica, 5 Feb. 2022 For at least 30 million years, bone-eating worms have been making their homes in the bodies of decomposing whales on the seabottom, but the rotting cetacean carcasses are not just food sources for the polychaetes. Brian Switek, WIRED, 23 Apr. 2010

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'polychaete.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


from the stem of New Latin Polychaeta, class name, neuter plural noun based on Greek polychaítēs "having abundant hair," from poly- poly- + -chaitēs, adjective derivative of chaítē "hair, flowing locks, mane of a horse" — more at chaeta

Note: The taxon Polychaeta was introduced as a modifier—Appendiculata polychaeta "those having appendages with many bristles"—by the German zoologist Adolph Eduard Grube (1812-80) in "Die Familien der Annelida," Archiv für Naturgeschichte, 16. Jahrgang (1850), 1. Band, p. 274.Compare oligochaete.

First Known Use

1891, in the meaning defined above

Time Traveler
The first known use of polychaete was in 1891

Dictionary Entries Near polychaete

Cite this Entry

“Polychaete.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polychaete. Accessed 28 Nov. 2022.

More from Merriam-Webster on polychaete

Love words? Need even more definitions?

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

The Great British Vocabulary Quiz

  • union jack speech bubble
  • Named after Sir Robert Peel, what are British police called?
True or False

Test your knowledge - and maybe learn something along the way.

Universal Daily Crossword

A daily challenge for crossword fanatics.