truncus

noun4

1. •
   The thorax of an insect.
2. •
   The trunk (torso) of the human body or other animal body.
3. •
   An arterial trunk, such as the truncus arteriosus.
4. •
   A curve in the Cartesian plane consisting of all points (x,y) satisfying an equation of the form f(x)=a/(x+b)²+c where a, b, and c are given constants.