Synonyms: unflurried, unflustered, unperturbed, unruffled
Definition: free from emotional agitation or nervous tension
Usage: the waiters were unflurried and good natured; with contented mind and unruffled spirit- Anthony Trollope
Similar words: composed
Definition: serenely self-possessed and free from agitation especially in times of stress
Usage: the performer seemed completely composed as she stepped onto the stage; I felt calm and more composed than I had in a long time