Wordnet 3.0
NOUN (1)
1. 
 primitive echinoderms having five or more feathery arms radiating from a central disk; 
ADJECTIVE (1)
1. 
 of or relating to or belonging to the class Crinoidea; 
The Collaborative International Dictionary of English v.0.48:
Crinoid \Cri"noid\ (kr[imac]"noid), a. [See Crinoidea.]
   (Zool.)
   Crinoidal. -- n. One of the Crinoidea.
   [1913 Webster]
WordNet (r) 3.0 (2006):
crinoid
    adj 1: of or relating to or belonging to the class Crinoidea
    n 1: primitive echinoderms having five or more feathery arms
         radiating from a central disk