IPA: /ɪmˈprɒpəli/
KK: /ɪmˈprɑpərli/
In a way that is not correct, suitable, or acceptable.
He spoke improperly during the meeting, which upset many people.
Improperly → It is formed from "im-" (meaning not) and "proprius" (from Latin, meaning one's own or proper) and the suffix "-ly" (meaning in a manner). The word "improperly" means in a manner that is not proper or suitable.
Think of 'not' ('im-') being combined with 'proper' ('proprius') to remember that 'improperly' means doing something in a way that is not proper.