(n.) Control over one's own feelings, temper, etc.; self-control.

aplomb assurance balance composure confidence constraint control discipline equability equanimity equilibrium independence level head levelheadedness poise possession presence of mind restraint self-assurance self-confidence self-conquest self-containment self-control self-denial self-discipline self-government self-mastery self-possession self-restraint uncommunicativeness well-regulated mind willpower