aplomb

confidence, assurance, self-possession, aplomb mean a state of mind or a manner marked by easy coolness and freedom from uncertainty, diffidence, or embarrassment. confidence stresses faith in oneself and one's powers without any suggestion of conceit or arrogance <the confidence that comes from long experience>. assurance carries a stronger implication of certainty and may suggest arrogance or lack of objectivity in assessing one's own powers <handled the cross-examination with complete assurance>. self-possession implies an ease or coolness under stress that reflects perfect self-control and command of one's powers <answered the insolent question with complete self-possession>. aplomb implies a manifest self-possession in trying or challenging situations <handled the reporters with great aplomb>.