A more thorough explanation:

Filing is the act of submitting a particular document, such as a pleading, to a court clerk or record custodian.

The lawyer argued that the plaintiff's most recent filing was not relevant to the issue before the court.

Another example of filing could be a person submitting their tax return to the Internal Revenue Service (IRS). This document would be considered a filing because it is being submitted to a record custodian.

These examples illustrate the definition of filing because they both involve submitting a document to a record custodian or court clerk.