IPA: //ʌnˈfɪtɪŋ//
KK: /ʌnˈfɪtɪŋ/
Not suitable or appropriate for a particular purpose or situation.
The dress was unfitting for the formal event, as it was too casual.
Unfitting → It is formed from "un-" (meaning not) and "fitting" (from Old English "fittan", meaning to fit or to be suitable). The word "unfitting" means not suitable or not appropriate for a particular purpose or situation.
Think of 'not' ('un-') being added to 'fitting', which means suitable — so unfitting describes something that is not suitable.