confidence (n.) Look up confidence at Dictionary.com
early 15c., from Middle French confidence or directly from Latin confidentia, from confidentem (nominative confidens) "firmly trusting, bold," present participle of confidere "to have full trust or reliance," from assimilated form of com, here probably an intensive prefix (see com-), + fidere "to trust" (see faith). For sense of "swindle" see con (adj.).