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

Common causes include loose or settling soil, improper planting depth, an uneven root ball, strong winds, and inconsistent watering, which can allow the root ball to shift before new roots are established. — Bianca Lambert, Southern Living, 15 Aug. 2026

This can stem from improper product layering, barrier disruption, over-cleansing, and more. — Brianna Peters, Vogue, 13 Aug. 2026

The report states Hackett faces charges of improper display of tags, a restriction on vehicle lamps, no seat belt, purchase or possession of alcohol by a minor and refusal to submit to arrest. — Arkansas Online, 13 Aug. 2026

However, registration isn't mandatory for convictions involving an improper relationship between an educator and a student. — Mateo Rosiles, USA Today, 13 Aug. 2026