Definition of Holothurioidea
: a class of echinoderms comprising the sea cucumbers and having a more or less elongate form usually with well-marked bilateral symmetry and differentiated dorsal and ventral surfaces, a flexible but tough and muscular body with the skeleton reduced to scattered ossicles or spicules, a water-vascular system with radial ambulacral vessels and tube feet for creeping, respiratory trees, Cuvierian organs, and strong branched tentacles about the mouth — compare trepang
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something valued as if it were money
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