- 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.
- (especially of the Tunicata) having a tunic or covering.
- of or relating to the tunicates.
- having or consisting of a series of concentric layers, as a bulb.
- any minute primitive marine chordate animal of the subphylum Tunicata (or Urochordata, Urochorda). The adults have a saclike unsegmented body enclosed in a cellulose-like outer covering (tunic) and only the larval forms have a notochord: includes the sea squirts
- of, relating to, or belonging to the subphylum Tunicata
- (esp of a bulb) having or consisting of concentric layers of tissue
