1 : something established by authority, custom, or general consent as a model, example, or point of reference [the of the reasonable person]
2 : something established by authority as a rule for the measure of quantity, weight, extent, value, or quality
3 : the basis of value in a monetary system
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.