term:

Prudent Man Rule

prudent man rule n

: a rule giving discretion to a fiduciary and esp. a trustee to manage another's affairs and invest another's money with such skill and care as a person of ordinary prudence and intelligence would use in managing his or her own affairs or investments called also prudent person rule compare legal list

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.