confidence
/ˈkän-fə-dən(t)s/
noun
a feeling or consciousness of one's powers or of reliance on one's circumstances
faith or belief that one will act in a right, proper, or effective way
the quality or state of being certain : certitude
had perfect confidence in her ability to succeed
have confidence in a leader
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. assurance carries a stronger implication of certainty and may suggest arrogance or lack of objectivity in assessing one's own powers.
adjective
of, relating to, or adept at swindling by false promises
a confidence game
noun
a group of continuous or discrete adjacent values that is used to estimate a statistical parameter (such as a mean or variance) and that tends to include the true value of the parameter a predetermined proportion of the time if the process of finding the group of values is repeated a number of times