Wiktionary
vb. 1 (context transitive English) To pack into boxes. 2 (context transitive English) To confine.
WordNet
v. enclose or confine as if in a box [syn: box in]
Usage examples of "box up".
Then I fell, tail down, box up, on top of the skidding sled and went with it down the Poodleville hill .
She lifted the rosewood box up to a canister light on the wall and began examining the underside of the lid.
They pried and grunted and heaved and finally got the box up on its side.
He lifted the box up onto the table and laid it there, opening the lid for Hempton to look inside.
She helped him to his feet and he saw that Knocker, with the strength of a madman, was pushing the box up and into the cart.
He looked surprised when I asked him to lift the box up again so that I could spread a newspaper under it.