Hydractinia

noun

Hy·​drac·​tin·​ia

ˌhīˌdrakˈtinēə

: a genus of marine hydroids that have separate and distinctive polyps for nutritive, reproductive, and defensive functions borne on a dense encrusting coenosarc and that are commonly associated with shells containing hermit crabs

hydractinian

¦⸗ˌ⸗¦tinēən

adjective or noun

Word History

Etymology

New Latin, from hydr- + Actinia

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