A document that is filed or introduced in evidence in a lawsuit, as in the phrases papers in the case and papers on appeal.
Any written or printed statement, including letters, memoranda, legal or business documents, and books of account, in the context of the Fourth Amendment to the U.S. Constitution, which protects the people from unreasonable searches and seizures with respect to their "papers" as well as their persons and houses.
In the context of accommodation paper and Commercial Paper, a written or printed evidence of debt.