From WordNet (r) 3.0 (2006) [wn]:
container
n 1: any object that can be used to hold things (especially a
large metal boxlike object of standardized dimensions that
can be loaded from one form of transport to another)
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Container \Con*tain"er\, n.
1. One who, or that which, contains; particularly, an
artifactual object that is designed to contain some fluid
or solid material, object or objects, especially for
convenience in transporting the contained objects.
[1913 Webster]
2. a large metallic box designed to hold many smaller boxes
or packages, and used for convenience in loading and
unloading large quantities of freight, such as on ships,
trains, or airplanes.
[PJC]