noun. primitive echinoderms having five or more feathery arms radiating from a central disk.
1. Noun, singular or mass The term Indian money is a misnomer, as these relics are in fact fossil remains of a sea creature known as a crinoid. 2. Adjective Another indication of the widespread range of the now extinct crinoids and their large numbers are the large limestone deposits in North America and Europe that are made of crinoid pieces.