IPA: /ˌʌn.fəˈɡɪv.ɪŋ/
KK: /ʌnˈfɚˌgɪvɪŋ/
Not willing to forgive or show mercy; harsh and strict, often not allowing for mistakes or weaknesses.
The unforgiving nature of the exam made many students anxious.
Unforgiving → It is formed from "un-" (meaning not) and "forgiving" (from Old English "forgiefan", meaning to give up resentment or pardon). The word "unforgiving" means not willing to forgive or show mercy.
Think of 'not' ('un-') being added to 'giving up resentment' ('forgiving') — that's why unforgiving means someone who does not let go of anger.