adj. adj. Consisting of, or containing, vessels as an essential part of a structure; full of vessels; specifically (Bot.), pertaining to, or containing, special ducts, or tubes, for the circulation of sap.adj. Operating by means of, or made up of an arrangement of, vesselsadj. Of or pertaining to the vessels of animal and vegetable bodies.adj. Of or pertaining to the higher division of plants, that is, the phænogamous plants, all of which are vascular, in distinction from the cryptogams, which to a large extent are cellular only.