1) Best way to defuse a bomb 2) In a composed manner 3) In a non-panicky way 4) In a sedate manner 5) In a serene way 6) Levelly 7) Quietly, without fuss 8) Sans anxiety 9) Sedately 10) Sensibly 11) Steadily 12) Unemotionally 13) With composure 14) With equanimity 15) With no trace of panic 16) With self-possession 1) Consistently 2) Demurely 3) Evenly 4) Gently 5) In stride 6) Quietly 7) Sedately 8) Serenely 
• (adv.) In a calm manner.
Calm'ly adverb In a calm manner. « The gentle stream which calmly flows. Denham. » 
[adv] - with self-possession (especially in times of stress)
adverb with self-possession (especially in times of stress); `he spoke calmly to the rioting students`