High misdemeanor is an archaic term in English Law for a number of positive misprisions, neglects and contempts.
A good example of this is treason.
The most important example may be that of maladministration in high office.
A number of United Kingdom statutes refer to particular crimes as being high misdemeanors: Blackstone describes a number of offences as being high misdemeanors, for example: A number of statutory references to high misdemeanors have subsequently been repealed, including: