main or central stem of a tree (see bole and stem).
Merriam-Webster Online Dictionary
trunk (noun)1.
a) the main stem of a tree apart from limbs and roots - called also bole
b) (1) the human or animal body apart from the head and appendages - torso
(2) the thorax of an insect
c) the central part of anything , specifically the shaft of a column or pilaster
2.
a) (1) a large rigid piece of luggage used usually for transporting clothing and personal effects
(2) the luggage compartment of an automobile
b) (1) a superstructure over a ship's hatches usually level with the poop deck
(2) the part of the cabin of a boat projecting above the deck
(3) the housing for a centerboard or rudder
3.
- proboscis , especially the long muscular proboscis of the elephant
4.
men's shorts worn chiefly for sports - swimming trunks
5.
a) a usually major channel or passage (as a chute or shaft)
b) a circuit between two telephone exchanges for making connections between subscribers , broadly a usually electronic path over which information is transmitted (as between computer systems)
6.
a) the principal channel or main body of a system or part that divides into branches - a nerve trunk the trunk of a river
b) - trunk line