In botany, trunk usually refers to the single main woody axis of substantial height of a tree that is supported by and directly attached to the roots at or near ground level and which in turn supports the canopy.
The trunk of a tree is also often called the bole. The trunk is usually covered with bark; Some trees may have more than one trunk.

In a more general mining a trunk is any main, basal stem or branch , usually vertical of a plant (tree, shrub, vine, herb or succulent) which supports all the top parts like branches, leaves and flowers.