IPA: /ˌɪnəˈproʊpriətli/
KK: /ɪnəˈprɑːpriətli/
In a way that is not proper or suitable for a particular situation.
He spoke inappropriately during the meeting, making everyone uncomfortable.
Inappropriately → It is formed from "in-" (meaning not), "appropriate" (from Latin "appropriatus", meaning to make suitable or proper), and "-ly" (meaning in a manner). The word describes an action that is not suitable or proper in a given context.
Think of 'not' ('in-') doing something 'suitable' ('appropriate') — that's why inappropriately means acting in a way that is not suitable.