- 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
SynonymsSee more synonyms for on Thesaurus.com
Examples from the Web for improper
Farrell issued a ticket to an 18-year-old shipyard worker for speeding and an improper exhaust mechanism, according to the TP.The Louisiana Racists Who Courted Steve Scalise
January 3, 2015
And if any police were warning bars against serving the Santas, “that would be improper behavior by a government official.”Before the Bros, SantaCon Was as an Anti-Corporate Protest
December 12, 2014
I feel sorry because (patients) got the surgery with improper devices, so they might suffer from it.Patients Screwed in Spine Surgery ‘Scam’
The Center for Investigative Reporting
November 3, 2014
It could be that those downstream abnormalities in cell development were due to improper signaling from the cerebellum.Early Brain Injury Might Be the Root of Autism
September 7, 2014
Improper burial, Dove says, could mean that harmful bacteria are leeching into the waterways.Aporkalypse Now: Pig-Killing Virus Could Mean the End of Bacon
August 20, 2014
For my own part, I thought pride in his case an improper subject for raillery.Clarissa, Volume 1 (of 9)
It is also, in the present acceptation of the word, improper.Female Scripture Biographies, Vol. II
Francis Augustus Cox
Before we quit this island, it will not, perhaps, be improper to mention some things about it.The History of Louisiana
Le Page Du Pratz
I am but the son of poor parents, and may have been tempted to some things that are improper.Homeward Bound
James Fenimore Cooper
The improper connections were soon removed and others substituted.Tom Swift and his Electric Runabout
- lacking propriety; not seemly or fitting
- unsuitable for a certain use or occasion; inappropriatean improper use for a tool
- irregular or abnormal
Word Origin and History for improper
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.).