improper
Americanadjective
-
not proper; not strictly belonging, applicable, correct, etc.; erroneous.
He drew improper conclusions from the scant evidence.
- Synonyms:
- unfit, unsuited, inapplicable
-
not in accordance with propriety of behavior, manners, etc..
improper conduct at a funeral.
- Synonyms:
- indecorous, unfit, unsuited, inapplicable
- Antonyms:
- proper
-
unsuitable or inappropriate, as for the purpose or occasion.
improper attire for a formal dance.
- Synonyms:
- unfit, unsuited, inapplicable
-
abnormal or irregular.
improper functioning of the speech mechanism.
adjective
-
lacking propriety; not seemly or fitting
-
unsuitable for a certain use or occasion; inappropriate
an improper use for a tool
-
irregular or abnormal
Usage
What does improper mean? Improper describes something considered unsuitable or inappropriate for the purpose or occasion, as in A ballgown is improper dress for playing basketball. Improper also describes something that isn’t appropriate for a specific scenario or circumstance, as in Shouting out the answers during a silent test is generally considered improper. Improper can also describe something that is not correct, such as with an inaccurate conclusion or faulty language usage. Finally, improper can be used to describe something as abnormal or irregular, particularly in reference to how something mechanical operates. Example: We knew the test readouts were improper because the results were physically impossible.
Related Words
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.
Other Word Forms
- improperly adverb
- improperness noun
Etymology
Origin of improper
From the Latin word improprius, dating back to 1535–45. See im- 2, proper
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
He said the company self-reported improper conduct by an individual employee during that period.
From The Wall Street Journal • Apr. 1, 2026
Other suspected fraud schemes involve enrolling beneficiaries without their consent and improper billing practices.
From MarketWatch • Mar. 24, 2026
"If people think there is anything improper in this, they should report us. They won't because there isn't," he said.
From BBC • Mar. 17, 2026
CHP officials regularly conduct enforcement operations targeting improper use of carpool lanes, including drivers attempting to evade rules by using mannequins or other objects to mimic passengers.
From Los Angeles Times • Mar. 17, 2026
Baker decided it would be professionally improper to push his opposing view when he hadn't examined the wound.
From "Ambushed!" by Gail Jarrow
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
