[L.: see TRUNK.] a. Anat. The trunk or main stem of a vessel or nerve. b. Zool. The trunk or body of an animal, without the head, limbs, and tail; in Entom. the thorax. c. Bot. The trunk or stem of a tree.
1693. trans. Blancard’s Phys. Dict. (ed. 2), Truncus, in general … that part of the great Artery and Vena Cava, which descends from the Heart … more especially … those Branches which are sent from the great Trunk to the Visera.
1706. Phillips (ed. Kersey), Truncus, (Lat.) the Stem or Stock of a Tree without the Boughs; a Body without a Head.
1875. Huxley & Martin, Elem. Biol. (1883), 177. As the truncus becomes more and more distended, the longitudinal valve … tends more and more completely to shut off the openings of the pulmonary arteries.
