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

However, Walk said on Thursday that reports show improper payments could be as high as 10%. —CBS News, 16 Apr. 2026

Mandelson, who has denied doing anything improper, has not been charged. —ABC News, 16 Apr. 2026

And improper cleaning can be just as damaging as neglect. —Kate Van Pelt, The Spruce, 14 Apr. 2026

Shelby Dawn Lashombe, 25, a former teacher at Valley Mills High School in Valley Mills, pleaded guilty to two counts of improper relationship between educator and student, the McLennan County District Attorney’s Office confirmed to PEOPLE. —Kc Baker, PEOPLE, 13 Apr. 2026