im·​prop·​er (ˌ)im-ˈprä-pər How to pronounce improper (audio)
: not proper: such as
: not in accord with propriety, modesty, good manners, or good taste
improper language
: not suited to the circumstances, design, or end
improper medicine
: not regularly or normally formed or not properly so called
: not in accord with fact, truth, or right procedure : incorrect
improper inference
improperly adverb
improperness noun
Choose the Right Synonym for improper

indecorous, improper, unseemly, unbecoming, indelicate mean not conforming to what is accepted as right, fitting, or in good taste.

indecorous suggests a violation of accepted standards of good manners.

indecorous behavior

improper applies to a broader range of transgressions of rules not only of social behavior but of ethical practice or logical procedure or prescribed method.

improper use of campaign contributions

unseemly adds a suggestion of special inappropriateness to a situation or an offensiveness to good taste.

remarried with unseemly haste

unbecoming suggests behavior or language that does not suit one's character or status.

conduct unbecoming to an officer

indelicate implies a lack of modesty or of tact or of refined perception of feeling.

indelicate expressions for bodily functions

Examples of improper in a Sentence

The doctor gave him an improper diagnosis. They claim to have evidence of improper police conduct. improper use of public land This is an improper diet for a growing teenager. It would be improper for me to ask such a favor of her. He made some improper remarks.
Recent Examples on the Web Scientists from the California Department of Fish and Wildlife inspect the property for improper water discharge. Connor Sheets, Los Angeles Times, 8 June 2024 The Delaware Chancery Court ruled that there was a lack of independence among directors and that improper negotiations took place between Musk and the board. Rachel Ventresca, Fortune, 7 June 2024 The president has denied any wrongdoing, and the House GOP's investigation has yet to yield any evidence of improper conduct by Mr. Biden. Melissa Quinn, CBS News, 5 June 2024 Tarrant County’s district attorney has investigated 12 complaints about improper voting since an election integrity task force was formed in February 2023. Noah Alcala Bach, Fort Worth Star-Telegram, 5 June 2024 See all Example Sentences for improper 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'improper.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English, from Middle French impropre, from Latin improprius, from in- + proprius proper

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of improper was in the 15th century

Dictionary Entries Near improper

Cite this Entry

“Improper.” Dictionary, Merriam-Webster, Accessed 19 Jun. 2024.

Kids Definition


im·​prop·​er (ˈ)im-ˈpräp-ər How to pronounce improper (audio)
: not proper, right, or suitable
improperly adverb

Legal Definition


: not proper: as
: not in accord with correct procedure
an improper venue
: wrongful
specifically : in violation of a constitution
the denial of trial by jury was held improper
improperly adverb

More from Merriam-Webster on improper

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