Choose the adjective serene to describe someone who is calm and untroubled. If you tell someone horrible news and they remain serene, you might wonder if they heard you!
Related to the Latin word serenus "peaceful, calm, clear," serene was originally used in English, as in Latin, to describe calm weather. By the mid 1600s, however, it was used figuratively to describe a calm, untroubled person as well. Though people show their emotions pretty openly today, Victorian novels are full of characters who remain serene no matter how terrible the news.