improper

[ im-prop-er ]
/ ɪmˈprɒp ər /

adjective

not proper; not strictly belonging, applicable, correct, etc.; erroneous: He drew improper conclusions from the scant evidence.
not in accordance with propriety of behavior, manners, etc.: improper conduct at a funeral.
unsuitable or inappropriate, as for the purpose or occasion: improper attire for a formal dance.
abnormal or irregular: improper functioning of the speech mechanism.

Origin of improper

From the Latin word improprius, dating back to 1535–45. See im-2, proper
SYNONYMS FOR improper
2 indecorous. Improper, indecent, unbecoming, unseemly are applied to that which is unfitting or not in accordance with propriety. Improper has a wide range, being applied to whatever is not suitable or fitting, and often specifically to what does not conform to the standards of conventional morality: improper diet; improper behavior in church; improper language. Indecent, a strong word, is applied to what is offensively contrary to standards of propriety and especially of modesty: indecent behavior, literature. Unbecoming is applied to what is especially unfitting in the person concerned: conduct unbecoming a minister. Unseemly is applied to whatever is unfitting or improper under the circumstances: unseemly mirth.
Related formsim·prop·er·ly, adverbim·prop·er·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for improper

British Dictionary definitions for improper

improper

/ (ɪmˈprɒpə) /

adjective

lacking propriety; not seemly or fitting
unsuitable for a certain use or occasion; inappropriatean improper use for a tool
irregular or abnormal
Derived Formsimproperly, adverbimproperness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for improper

improper


adj.

mid-15c., "not true," from French impropre (14c.), from Latin improprius, from assimilated form of in- "not, opposite of" (see in- (1)) + proprius (see proper). Meaning "not suited, unfit" is from 1560s; that of "not in accordance with good manners, modesty, decency" is from 1739. Related: Improperly (late 14c.).

Online Etymology Dictionary, © 2010 Douglas Harper