IPA: /ˌɪnəˈproʊprɪt/
KK: /ɪnəˈproʊprɪt/
Not suitable or proper for a particular situation or context.
Making jokes during a serious meeting is considered inappropriate behavior.
Inappropriate → It is formed from "in-" (meaning not) and "appropriatus" (from Latin, meaning to make suitable or to take for oneself). The word "inappropriate" means not suitable or not proper for a particular situation.
Think of 'not' ('in-') being added to 'suitable' ('appropriatus') — this helps you remember that inappropriate means something that is not suitable.