Meaning of burden of proof

bur'den of proof'

Pronunciation: [key]
  1. the obligation to offer evidence that the court or jury could reasonably believe, in support of a contention, failing which the case will be lost.
  2. the obligation to establish a contention as fact by evoking evidence of its probable truth.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.