indecorous, improper, unseemly, unbecoming, indelicate mean not conforming to what is accepted as right, fitting, or in good taste. indecorous suggests a violation of accepted standards of good manners.

Definition of improper adjective from the Oxford Advanced Learner's Dictionary. dishonest, or morally wrong. He had been indulging in improper business practices. She was suspended for improper …

1. not proper; not strictly belonging, applicable, or correct: drew improper conclusions. 2. not in accordance with propriety or regulations: improper conduct. 3. abnormal; irregular.

improper adjective (WRONG) unsuitable or not correct for a particular use or occasion: improper prescription of medicines

If you describe someone's behavior as improper, you mean it is rude or shocking or in some way socially unacceptable. Such improper behavior and language from a young lady left me momentarily …

unsuitable or inappropriate, as for the purpose or occasion: improper attire for a formal dance. abnormal or irregular: improper functioning of the speech mechanism.

IMPROPER definition: not proper; not strictly belonging, applicable, correct, etc.; erroneous. See examples of improper used in a sentence.

Nov 30, 2025 · improper (comparative more improper, superlative most improper) Unsuitable to needs or circumstances; inappropriate; inapt. Not in keeping with conventional mores or good manners; …

It would be improper for me to ask such a favor of her. He made some improper remarks. He came to school improperly dressed. She pronounced the word improperly.

There are five meanings listed in OED's entry for the adjective improper, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.