IPA: /træŋˈkwɪl.nəs/
KK: /træŋˈkwɪl.nəs/
The state of being calm and peaceful, without disturbance or agitation.
She found tranquility in the quiet of the forest.
Tranquilness → It is formed from "tranquil" (from Latin "tranquillus", meaning calm or quiet) and the suffix "-ness" (meaning the state or quality of). The word "tranquilness" refers to the state of being calm or peaceful.
Think of the word 'tranquil' which means calm, and remember that 'tranquilness' describes the state of being calm.