IPA: /ˈstɪl.nəs/
KK: /ˈstɪl.nəs/
The condition of being quiet and calm, without movement or noise.
In the early morning, the stillness of the lake was peaceful and serene.
Stillness → It is formed from "still" (from Old English *stille*, meaning quiet or calm) and the suffix "-ness" (meaning the state or quality of). The word "stillness" refers to the state of being quiet or calm.
Think of the word 'still' meaning quiet or calm, and remember that 'stillness' describes the quality of being in that calm state.