confide: [15] To confide in somebody is literally to ‘put one’s trust or faith’ in them. The word comes from the Latin compound verb confidere, which was formed from the intensive prefix com- and fidere ‘trust’. This was a derivative of fides ‘trust’ (whence English faith). Confidant [16] and confidence [15] come from the Latin verb’s present participle, confīdēns, in which the secondary notion of ‘self-assurance’ was already present. The abbreviation con for confidence man, confidence trick, etc originated in the USA in the late 19th century. => confident, faith[confide etymology, confide origin, 英语词源]