Dictionary:

crinoid

  (krī'noid')

Any of various echinoderms of the class Crinoidea, including the sea lilies and feather stars, that are characterized by a cup-shaped body, feathery radiating arms, and either a stalk or clawlike structure with which they are able to attach to a surface.

Of or belonging to the Crinoidea.

[From New Latin Crinoīdea, class name : Greek krinon, lily + Greek -oeidēs, -oid.]

The noun has one meaning:

Meaning #1: primitive echinoderms having five or more feathery arms radiating from a central disk

The adjective crinoid has one meaning:

Meaning #1: of or relating to or belonging to the class Crinoidea
  Pertains to noun: Crinoidea (meaning #1)