tunicate

UK: /ˈtjuːnɪkɪt/ US: (to̅o̅′ni kit, -kāt′, tyo̅o̅′-)

WordReference Random House Unabridged Dictionary of American English © 2026

tu•ni•cate  (to̅o̅′ni kit, -kāt′, tyo̅o̅′-), n. 

1. Zoology 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.

adj. Also, tu′ni•cat′ed. 

2. (esp. of the Tunicata) having a tunic or covering.
3. Zoology of or pertaining to the tunicates.
4. Botany having or consisting of a series of concentric layers, as a bulb.

• Latin tunicātus wearing a tunic. See tunic, -ate¹
• 1615–25

Collins Concise English Dictionary © HarperCollins Publishers::

tunicate / ˈtjuːnɪkɪt -ˌkeɪt/ noun

1. 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
   See also ascidian

adjective
also: tunicated

1. (esp of a bulb) having or consisting of concentric layers of tissue

Etymology: 18th Century: from Latin tunicātus clad in a tunic