Pronunciation: (ku-lab'u-rāt"), [key]
—v.i., -rat•ed, -rat•ing.
1. to work, one with another; cooperate, as on a literary work: They collaborated on a novel.
2. to cooperate, usually willingly, with an enemy nation, esp. with an enemy occupying one's country: He collaborated with the Nazis during World War II.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.