Synonyms of improper

Adjective

1. improper (vs. proper), indecent, indecorous, unbecoming, uncomely, unseemly, untoward, out-of-the-way, wrong, incorrect, inappropriate, indecent, indecorous#1, indelicate, unfit, wrong

usage: not suitable or right or appropriate; "slightly improper to dine alone with a married man"; "improper medication"; "improper attire for the golf course"

2. improper, unconventional, unlawful, irregular (vs. regular)

usage: not conforming to legality, moral law, or social convention; "an unconventional marriage"; "improper banking practices"

3. improper, wrong, inappropriate (vs. appropriate)

usage: not appropriate for a purpose or occasion; "said all the wrong things"

Definition and meaning of improper (Dictionary)