substandard

adjective

deviating from or falling short of a standard or norm: such as: of a quality lower than that prescribed by law
deviating from or falling short of a standard or norm: such as: conforming to a pattern of linguistic usage existing within a speech community but not that of the prestige group in that community
deviating from or falling short of a standard or norm: such as: constituting a greater than normal risk to an insurer