tunicate

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various chordate marine animals of the subphylum Urochordata (or Tunicata), having a cylindrical or globular body enclosed in a tough outer covering and a notochord in the larval stage, and including the sea squirts and salps.
• adjective Of or relating to the tunicates.
• adjective Anatomy Having a tunic.
• adjective Botany Having a tunic, as the bulb of an onion.

from The Century Dictionary.

• In zoology, coated; covered with tunics or integuments; specifically, enveloped in membranous integuments or tunics, as an ascidian; of or pertaining to the Tunicata; tunicated.
• In entomology, covered one by another, like a set of thimbles, as the joints of some antennæ.
• In botany, covered with a tunic or membrane; coated.
• noun A tunic.
• noun An ascidian, tunicary, or sea-squirt; any member of the Tunicata.

from the GNU version of the Collaborative International Dictionary of English.

• proper noun (Zoöl.) One of the Tunicata.
• adjective (Bot.) Covered with a tunic; covered or coated with layers.
• adjective Having a tunic, or mantle; of or pertaining to the Tunicata.
• adjective Having each joint buried in the preceding funnel-shaped one, as in certain antennæ of insects.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any of very many chordate marine animals, of the subphylum Tunicata or Urochordata, including the sea squirts.
• adjective Of or pertaining to these animals.
• adjective anatomy, botany Enclosed in a tunic or mantle; covered or coated with layers.
• adjective zoology Having each joint buried in the preceding funnel-shaped one, as in certain antennae of insects.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva