Word Type

Adjective

Adjective

Verb

The word "improper" can be used as adjective, adjective and verb.

Word Relationships

Opposites (Antonyms)

proper

Derived Terms

improper divisor improper face improper fit improper fraction improper integral improper motion improper node improper noun improper orthogonal transformation improper rotation improper time improper use improper workmanship improperness

Derived From

improbity

Related Terms

appropriate circumstance consistent conventional erroneous fact immodest improper fraction improperly in keeping with inaccurate inappropriate inapt incorrect indecent indecorous limit manners mores named need unfit unsuitable wrong

Similar Terms

inappropriate inappropriate incorrect incorrect indecent indecorous indelicate irregular out of the way out of way out-of-the-way unbecoming unbecoming uncomely unfit unseemly untoward wrong

Synonym Network

inadequate inappropriate unconventional

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.