(a)confidenthaving or marked by confidence or assurance“a confident speaker”, “a confident reply”, “his manner is more confident these days”, “confident of fulfillment”
(s)convinced, positive, confidentpersuaded of; very sure“were convinced that it would be to their advantage to join”, “I am positive he is lying”, “was confident he would win”
(s)confident, surefooted, sure-footednot liable to error in judgment or action“most surefooted of the statesmen who dealt with the depression” (Walter Lippman), “demonstrates a surefooted storytelling talent” (Michiko Kakutani)