improper

Etymology

From Middle French impropre, from Latin improprius (“not proper”), from in- + proprius (“proper”).

adj

1. unsuitable to needs or circumstances; inappropriate; inapt
2. Not in keeping with conventional mores or good manners; indecent or immodest
   improper conduct
3. Not according to facts; inaccurate or erroneous
4. Not consistent with established facts; incorrect
5. Not properly named; See, for example, improper fraction
6. (obsolete) Not specific 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. 1608, John Fletcher, The Faithful Shepherdess
7. (mathematics) Of a complex random variable, correlated with its conjugate

verb

1. (obsolete, transitive) To appropriate; to limit.
   He would in like manner improper and inclose the sunbeams to comfort the rich and not the poor. 1565, John Jewel, letter to Thomas Harding
2. (obsolete) To behave improperly