| vein [vān] ANATOMY A relatively thin-walled blood vessel that carries blood from capillaries to the heart in vertebrates. BOTANY One of the vascular bundles in a leaf. GEOLOGY A mineral deposit in tabular or shell-like form filling a fracture in a host rock. INVERTEBRATE ZOOLOGY 1. One of the thick, stiff ribs providing support for the wing of an insect. 2. A venous sinus in invertebrates. |