nominal party

Definition from Nolo’s Plain-English Law Dictionary

A plaintiff or defendant in a lawsuit who may not have any actual interest or responsibility in a lawsuit but who is included because of technical reasons -- for example, an escrow company (temporarily holding title to property) may be named in a lawsuit over a real property sale. Without the nominal party, the court is unable to render the judgment to transfer the property. (See also: necessary party, party)

Definition provided by Nolo’s Plain-English Law Dictionary.