sb. pl. Phys. [L. adventīcia, pl. neut. of adj. adventīcius: see ADVENTITIOUS.] Membranous structure, usually morbid, covering but not belonging to an organ.
1876. trans. Wagner’s Gen. Pathol., 147. The adventitia of the large veins of the abdomen.
1878. Hamilton, Nerv. Dis., 18. Any adventitia that may be attached to the dura mater.
