Synonyms of improper

improper

adjective

(ˌ)im-ˈprä-pər 

as in inappropriate

not appropriate for a particular occasion or situation

an improper use of slang in a formal piece of writing

Synonyms & Similar Words

• inappropriate
• unsuitable
• incorrect
• wrong
• unfit
• unhappy
• irrelevant
• unfortunate
• unseemly
• indecorous
• incongruous
• out of place
• infelicitous
• unbecoming
• unacceptable
• inconsistent
• perverse
• out of the way
• inapt
• inept
• bad
• untoward
• amiss
• unapt
• awkward
• graceless
• inapposite
• untimely
• inopportune
• extraneous
• naughty
• unseasonable
• inapplicable
• malapropos
• incompatible
• forbidden
• immaterial
• sinful
• mismatched
• prohibited
• uncongenial
• unsatisfactory
• irrelative
• censurable
• blameworthy
• ungraceful
• disallowed
• barred
• blamable
• proscribed
• outlawed
• gauche
• banned
• misbecoming
• interdicted

Antonyms & Near Antonyms

• appropriate
• proper
• correct
• suitable
• right
• fitting
• relative
• happy
• timely
• meet
• relevant
• applicable
• becoming
• felicitous
• decorous
• fit
• opportune
• apt
• fortunate
• seasonable
• genteel
• permitted
• compatible
• material
• adequate
• harmonious
• congenial
• pointed
• authorized
• acceptable
• seemly
• pat
• satisfactory
• apposite
• befitting
• endorsed
• approved
• fine
• sanctioned
• decent
• promoted
• licensed
• supported
• kosher
• all right
• allowed
• tolerable
• respectable
• germane
• exemplary
• OK
• passable
• commendable
• creditable
• apropos
• encouraged
• balanced
• blameless
• consonant
• irreproachable
• abetted
• congruous
• companionate

Synonym Chooser

How does the adjective improper differ from other similar words?

Some common synonyms of improper are indecorous, indelicate, unbecoming, and unseemly. While all these words mean "not conforming to what is accepted as right, fitting, or in good taste," 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

When would indecorous be a good substitute for improper?

The synonyms indecorous and improper are sometimes interchangeable, but indecorous suggests a violation of accepted standards of good manners.

indecorous behavior

When is indelicate a more appropriate choice than improper?

The words indelicate and improper can be used in similar contexts, but indelicate implies a lack of modesty or of tact or of refined perception of feeling.

indelicate expressions for bodily functions

In what contexts can unbecoming take the place of improper?

While in some cases nearly identical to improper, unbecoming suggests behavior or language that does not suit one's character or status.

conduct unbecoming to an officer

When could unseemly be used to replace improper?

The words unseemly and improper are synonyms, but do differ in nuance. Specifically, unseemly adds a suggestion of special inappropriateness to a situation or an offensiveness to good taste.

remarried with unseemly haste

Example Sentences

Recent Examples of improper

Inspectors observed several critical violations, including improper cold and hot holding temperatures, unsafe food storage, and inadequate handwashing and glove practices, city officials said. —Lillie Davidson, Fort Worth Star-Telegram, 23 Apr. 2026

Major industry leaders, under pressure from lawmakers, have taken steps in recent months to mitigate the perception that their product is susceptible to improper wagering on insider information. —Lucien Bruggeman, ABC News, 22 Apr. 2026

This care is especially important for valuable books, as light exposure, improper handling, and environmental conditions can cause irreparable wear. —Olivia McIntosh, Martha Stewart, 22 Apr. 2026

Past fixes, like 2012’s Proposition B, failed in court due to improper negotiations. —Jacob Mitchell, San Diego Union-Tribune, 21 Apr. 2026