improper

US /ɪmˈprɑː.pɚ/
UK /ɪmˈprɑː.pɚ/
1.

khiếm nhả, không đúng, không hợp cách, không hợp phép, không lịch sự, không xứng đáng

not in accordance with accepted rules or standards, especially of morality or honesty.

:
he was accused of improper behavior in his business dealings