[ im-prop-er ]
/ ɪmˈprɒp ər /
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See synonyms for: improper / improperly / improperness on Thesaurus.com

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.
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Origin of improper

From the Latin word improprius, dating back to 1535–45. See im-2, proper

synonym study for improper

2. 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.


im·prop·er·ly, adverbim·prop·er·ness, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


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.

Where does improper come from?

The first records of the term improper come from around 1530. It ultimately comes from the Latin improprius.

Proper and improper are often used to describe public behaviors, manners, dress, language, and more, judging them against an ideal, which is sometimes unrealistic in an effort to keep people from obtaining it. One example of this is setting as proper a hairstyle that is impossible for some people. Any deviation from this hairstyle would be considered improper.

In the past, the term proper was often associated with people of upper-class society with “good” character or that lived “respectable” lifestyles. Improper by extension was used to describe people who did not live high society lifestyles, and was often used as an insult to describe people who received a lower income. Improper is still used in this way in certain cases, such as fine dining, special event planning, and dress.

Did you know … ?

What are some other forms related to improper?

  • improperly (adverb)
  • improperness (noun)

What are some synonyms for improper?

What are some words that share a root or word element with improper?

What are some words that often get used in discussing improper?

How is improper used in real life?

Generally, something that is improper is abnormal or irregular compared to what is expected in a given situation.



Try using improper!

Which of the following is NOT a synonym for improper?

A. irregular
B. inappropriate
C. incorrect
D. acceptable

How to use improper in a sentence

British Dictionary definitions for improper

/ (ɪmˈprɒpə) /

lacking propriety; not seemly or fitting
unsuitable for a certain use or occasion; inappropriatean improper use for a tool
irregular or abnormal

Derived forms of improper

improperly, 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