Not proper; not suitable; not fitted to the circumstances, design, or end; unfit; not becoming; incongruous; inappropriate; indecent; as, an improper medicine; improper thought, behavior, language, dress.
Not peculiar or appropriate to individuals; general; common.
Not according to facts; inaccurate; erroneous.
To appropriate; to limit.
improper in German is ungenau, nicht angemessen
improper in Norwegian is upassende