Define That Term #96

Sunday's term was repudiation, which is defined as:

n. denial of the existence of a contract and/or refusal to perform a contract obligation. Repudiation is an anticipatory breach of a contract. See also: contract anticipatory breach.

Slickdpdx's guess was close, although limited to the criminal context.

Taday's term is:

writ of coram nobis.

Good luck, and no dictionaries, please.