improper

adjective

im·​prop·​er (ˌ)im-ˈprä-pər 

: not proper: such as

a

: not in accord with propriety, modesty, good manners, or good taste

improper language

b

: not suited to the circumstances, design, or end

improper medicine

c

: not regularly or normally formed or not properly so called

d

: not in accord with fact, truth, or right procedure : incorrect

improper inference

improperly adverb

improperness noun

Synonyms

• inappropriate
• unsuitable
• incorrect
• wrong
• unfit
• unhappy

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

The new order said the justices were not making a final determination, but the administration had made sufficient showing at this stage that the challenge brought by foreign assistance groups to Trump's spending freeze was improper. —Maureen Groppe, USA Today, 26 Sep. 2025

Conversely, improper storage can lead to irreversible damage from moisture, pests, or accidents. —Nafeesah Allen, Better Homes & Gardens, 24 Sep. 2025

Sustained allegations include medication mismanagement due to lack of training, poor supervision of residents due to short-staffing and improper record-keeping, also due to inadequate training. —Daniel Lempres, Sacbee.com, 24 Sep. 2025

The group has formally contacted at least 17 of the institutions, alleging improper investigations or punishment of speech protected by the First Amendment. —Jesus Mesa, MSNBC Newsweek, 24 Sep. 2025

Word History

Etymology

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

First Known Use

15th century, in the meaning defined above

Phrases Containing improper

• improper fraction
• improper integral

Rhymes for improper

• eavesdropper
• grasshopper
• leafhopper
• sharecropper
• chopper
• copper
• cropper
• dropper
• pauper
• popper
• proper
• shopper

Kids Definition

improper

adjective

im·​prop·​er (ˈ)im-ˈpräp-ər 

: not proper, right, or suitable

improperly adverb

Legal Definition

improper

adjective

im·​prop·​er

: not proper: as

a

: not in accord with correct procedure

an improper venue

b

: wrongful

specifically : in violation of a constitution

the denial of trial by jury was held improper

improperly adverb