substantial or legally sufficient reason for doing something. For example, if a statute provides for granting a new trial upon a showing of good cause, such good cause might include the existence of fraud, lack of notice to the parties or newly discovered evidence.
EXAMPLE: Motions submitted before a judge, which in essence ask the judge to do something, must be supported by a showing of good cause. On a motion to exclude or suppress evidence for trial, good cause must be shown by example of illegal police conduct in the seizing of the evidence. For the motion to be granted, the judge must be convinced the conduct occurred and is enough to justify exclusion.
Source: Barron's Dictionary of Legal Terms, Steven H. Gifis, 5th Edition; © 2016