adventitia Adventist • adventitious · · · Info · Definitions · Synonyms · Characters · · adventitia · · Text Latin · · Script 10 · · Length Definitions · · · (noun) an enveloping or covering membrane or layer of body tissue. Synonyms: tunic, tunica. · · Noun Definition 1 Synonyms · · · tunic · · Synonym 1 tunica · · Synonym 2 Characters · · a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 n latin small letter n U+006E t latin small letter t U+0074 v latin small letter v U+0076