actinia

[ak-tin-ee-uh] /ækˈtɪn i ə/
noun, plural actiniae
[ak-tin-ee-ee] /ækˈtɪn iˌi/ (Show IPA),
actinias.
1.
a sea anemone, especially of the genus Actinia.
Origin
1740-50; < Neo-Latin; see actin-, -ia
British Dictionary definitions for actinia

actinia

/ækˈtɪnɪə/
noun (pl) -tiniae (-ˈtɪnɪˌiː), -tinias
1.
any sea anemone of the genus Actinia, which are common in rock pools
Word Origin
C18: New Latin, literally: things having a radial structure. See actino-, -ia