burden of proof

burden of proof   n.   Law The responsibility of proving a disputed charge or allegation.

Main Entry: bur·den of proof
: the responsibility of producing sufficient evidence in support of a fact or issue and favorably persuading the trier of fact (as a judge or jury) regarding that fact or issue burden of proof is sometimes upon the defendant to show his incompetency —W. Railroad LaFave and A. W. Scott, Junior> —compare STANDARD OF PROOF
NOTE: The legal concept of the burden of proof encompasses both the burdens of production and persuasion. Burden of proof is often used to refer to one or the other. Burden of proof and burden of persuasion are also sometimes used to refer to the standard of proof.

burden of proof

Obligation of proving a disputed charge or allegation. For example, Are you sure you mailed the tax return on time? The burden of proof's on you. A legal term dating from the late 1500s, it has also been used more loosely in recent times.