Composed, undisturbed, unruffled, or placid. Those words mean unperturbed.
Calm, unruffled, serene
unfazed
unperturbed
The boy was remarkably unperturbed by the terrible news.
The nasty argument left her unperturbed. (She was not bothered)
That is the correct spelling of the word "unperturbed" (unaffected, calm).
Despite the chaos around her, she remained unperturbed and continued to focus on her work.
He doesn't seem unperturbed by the comment Eric made.
Undisturbed, calm and collected
Not to disturb someone or something
びくともし