serene
adj. B2 Upper Intermediate US //sɝˈin// UK //səɹˈiːn// serene
adj. calm, peaceful, and without any worry. You use this to describe a person who is relaxed or a place that is very quiet and beautiful.
adj. marked by peacefulness and an absence of agitation or noise. Often used to describe landscapes or a person's facial expression and temperament.
The lake looked serene in the early morning light.
Despite the chaos of the busy airport, she remained serene and focused on her book.
The monk's serene expression suggested a deep internal peace that remained undisturbed by the loud construction occurring just outside the temple walls.
Usage
Typically used as a predicative adjective after 'look', 'seem', or 'remain', or as an attributive adjective before a noun.