polychaete
noun
poly·chaete ˈpä-lē-ˌkēt 
: 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
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 Word History
Etymology
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