(n.) Freedom from agitation or excitement of mind; coolness in trying circumstances; indifference; calmness.

Buddha-like composure Oriental calm aloofness aplomb ataraxy balance balanced personality calm disposition calm of mind calmness composure constancy cool coolheadedness coolness coolth countenance courage easy mind equanimity equilibrium fastness firmness homeostasis icy calm imperturbability imperturbation indifference indisturbance invariability mental composure nerve peace of mind peacefulness philosophic composure philosophicalness philosophy phlegm placidity poise quiet quiet mind quietude reliability rootedness sang-froid secureness security self-containment self-control self-possession serenity solidity soothingness soundness stability stable equilibrium stable state steadfastness steadiness steady nerves steady state substantiality tranquillity unconcern undeflectability uniformity unruffledness unshakable nerves unshakableness