1. 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. Follow'd his enemy king, and did him service, improper for a slave. (Shak) And to their proper operation still, Ascribe all Good; to their improper, ill. (Pope)
2. Not peculiar or appropriate to individuals; general; common. Not to be adorned with any art but such improper ones as nature is said to bestow, as singing and poetry. (j. Fletcher)
3. Not according to facts; inaccurate; erroneous. Improper diphthong. See diphthong. Improper feud, an originalfeud, not earned by military service. Mozley & W. Improper fraction. See fraction.
Origin: f. Impropre, L. Improprius; pref. Im- not _ proprius proper. See proper.