mumness means the quality of being mum or silent.
Etymology
From mum (“silent, secret”) + -ness.
noun
- The quality of being mum or silent.“Anthony accordingly was mum; but his mumness was visible. He wrapped himself up in secrecy and silence, but both his secrecy and his silence laid him open to the misgivings and the suspicions of those about him.”
- The state or quality of being a mum (mother).“‘Where did you go, love?’ Mum asks, but she asks as if she's not really interested, as if she isn't inside her body any longer, her comfortable familiar mumness.”