IPA: /ˈʃeɪmfəl.nəs/
KK: /ˈʃeɪmfəl.nəs/
The quality or state of being disgraceful or causing feelings of guilt and embarrassment.
The shamefulness of his actions was evident to everyone around him.
Shamefulness → It is formed from "shame" (from Old English "sceamu", meaning a feeling of guilt or disgrace) and "-fulness" (meaning the state of being full of). The word "shamefulness" refers to the state of being full of shame or the quality of being shameful.
Think of feeling 'full of' ('-fulness') guilt or disgrace ('shame') — that's what shamefulness means.