Prima facie

Latin for "at first sight."  Prima facie may be used as an adjective meaning "sufficient to establish a fact or raise a presumption unless disproved or rebutted;" e.g., prima facie evidence.  It may also be used as an adverb meaning "on first appearance but subject to further evidence or information;" e.g., the agreement is prima facie valid.

A prima facie case is the establishment of a legally required rebuttable presumption.  It is generally understood as a flexible evidentiary standard that measures the effect of evidence as meeting, or tending to meet, the proponent's burden of proof on a given issue.  In that sense, a prima facie case is a cause of action or defense that is sufficiently established by a party's evidence to justify a verdict in his or her favor, provided such evidence is not rebutted by the other party.

See, e.g., Bell Atlantic Corp. v. Twombly, 550 U.S. 554 (2007); Swierkiewicz v. Sorema N.A., 534 U.S. 506 (2002); Hernandez v. New York, 500 US 352 (1991).