tunic vs adventitia

tunic and adventitia both are nouns.

Word	Noun	Adjective	Verb	Adverb
tunic	Yes	No	No	No
adventitia	Yes	No	No	No

As nouns, tunic and adventitia are synonyms defined as:

tunic and adventitia: an enveloping or covering membrane or layer of body tissue

Other synonyms of tunic include tunica.

tunic (noun)	adventitia (noun)
any of a variety of loose fitting cloaks extending to the hips or knees	an enveloping or covering membrane or layer of body tissue
an enveloping or covering membrane or layer of body tissue