Pronunciation: (tOO'ni-kit, -kāt", tyOO'-), [key]
Zool.any sessile marine chordate of the subphylum Tunicata (Urochordata), having a saclike body enclosed in a thick membrane or tunic and two openings or siphons for the ingress and egress of water.
1. (esp. of the Tunicata) having a tunic or covering.
2. of or pertaining to the tunicates.
3. Bot.having or consisting of a series of concentric layers, as a bulb.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.