stillness
This word is typically used as an uncountable noun, meaning you do not usually say "stillnesses." It can describe both a physical environment (like a quiet room) and a mental state (like feeling peaceful). When describing a person's mind, it often carries a positive or spiritual meaning.
💬Casual Conversation
🎬Tuesday afternoon, Sarah is hiding in a quiet stairwell to avoid David.
Sarah
Hiding in the south stairs. The absolute stillness here is the only thing keeping me sane.
Jessica
Careful, David's on a rampage. He'll sniff you out in two seconds.
💡
Sarah uses 'stillness' to describe the physical silence of her hiding spot as a mental refuge from work stress. Jessica uses the idiom 'on a rampage' to describe their boss's current state of anger/urgency and 'sniff you out' to mean discovering someone's hidden location.