#tunic

• Tunica adnata — An old or restrictively used anatomical term as a noun to designate the conjunctive membrane of the eye (tunica adnata) or a transparent structure closely attached to the cornea; it reflects a complete structural fusion of periocular protective tissues. In modern current usage, the feminine adjectival form 'adnată' is primarily used in agreement with various organs.
• Adventitia — The plural form (or feminine singular in specific variants) for the adjective adventiv, describing organs, structures, or elements appearing in an unusual, accidental, or secondary location. In human histology and anatomy, it functions as a feminine noun (the adventitia), denoting the outermost connective tissue tunic shielding a blood vessel or a tubular organ, rich in collagen and elastic fibers. In botany, it points to roots or buds arising at atypical locations.
• Tunica albuginea — A dense, resistant, and pearly-white fibrous membrane, composed of compact connective tissue, that structurally envelops certain internal animal or human organs, such as the testes, ovaries, or corpora cavernosa; tunica albuginea.
• Ascidian — In zoology, a lower, sedentary marine animal from the tunicate phylum, having its body protected by a gelatinous or leathery tunic with two siphons through which water circulates. In botany, it represents a structurally modified leaf in the shape of a pitcher, urn, or cornet, specific to certain carnivorous plants (such as Nepenthes), adapted for capturing and digesting insects.