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

If you describe someone's behaviour as improper, you mean that it is rude or shocking.

Definition of improper adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

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

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. im•prop′er•ness, n.

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

Jan 24, 2026 · improper (comparative more improper, superlative most improper) Unsuitable to needs or circumstances; inappropriate; inapt. Not in keeping with conventional mores or good manners; …

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.

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.

Improper refers to something that is not suitable, correct, or appropriate according to rules, laws, social norms or standards. It may refer to behavior, language, actions or even objects that do not …