holothurian
noun
ho·lo·thu·ri·an ˌhō-lə-ˈthu̇r-ē-ən 
-ˈthyu̇r-,
ˌhä-
: sea cucumber
holothurian adjective
Example Sentences
Recent Examples on the Web Marine invertebrates—from octopuses to hermit crabs and creatures like the bizarre holothurians—are the focus of this photography book. 
Tim Flannery, The New York Review of Books, 7 Mar. 2019
Tim Flannery, The New York Review of Books, 7 Mar. 2019 Word History
Etymology
New Latin Holothuria, a sea cucumber genus (going back to Latin, plural of holothūrion, zoophyte-like sea creature of uncertain identity, borrowed from Greek holothoúrion, of obscure origin) + -an entry 1
First Known Use
circa 1842, in the meaning defined above