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

Cooked collard greens were held at improper hot holding temperatures. — Sacbee.com, 4 Sep. 2026

Cosmetic repairs, oil changes and tune-ups are also usually excluded, as are pre-existing issues and damage resulting from accidents, misuse, neglect or improper maintenance. — Brian Sloan, CNBC, 4 Sep. 2026

The official concluded that the primary risks from improper vetting include national security threats, insider compromise and the erosion of public trust in the agency. — Laura Romero, ABC News, 4 Sep. 2026

The report stated the franchise also covered personal expenses for Leonard and failed to report improper solicitations made by his former business manager and uncle, Dennis Robertson. — Wayne Sterling, CNN Money, 2 Sep. 2026