A bill of particulars is defined as a written itemization of claims in a lawsuit that the defendant may demand of the plaintiff in some situations in order to clarify the details of the claims.
See e.g., United States v. Davis 139 S.Ct. 2319 and Boumediene v. Bush 128 S.Ct. 2229.
[Last updated in July of 2022 by the Wex Definitions Team]