actinian
noun
ac·tin·i·an ak-ˈti-nē-ən 
: sea anemone
Word History
Etymology
New Latin Actinia, a sea anemone genus (from Greek aktīn-, aktís "ray, beam" + New Latin -ia -ia entry 1) + -an entry 1 — more at actin-
First Known Use
1869, in the meaning defined above