Con • fi • dence
confidence 
early 15c., from M.Fr. confidence or directly from L. confidentia, from confidentem (nom. confidens) “firmly trusting, bold,” prp. of confidere “to have full trust or reliance,” from com-, intensive prefix (see com-), + fidere “to trust” (see faith). For sense of “swindle” see con (3).
- full trust; belief in the powers, trustworthiness, or reliability of a person or thing: We have every confidence in their ability to succeed.
- belief in oneself and one’s powers or abilities; self-confidence; self-reliance; assurance: His lack of confidence defeated him.
- certitude; assurance: He described the situation with such confidence that the audience believed him completely.
- a confidential communication: to exchange confidences.
con (3) “swindling” (adj.), 1889, Amer.Eng., from confidence man (1849), from the many scams in which the victim is induced to hand over money as a token of confidence. Confidence with a sense of “assurance based on insufficient grounds” dates from 1590s. As a verb, “to swindle,” from 1896. Con also can be a slang or colloquial shortening of some nouns beginning in con-, e.g., from the 19th century, confidant, conundrum, conformist, convict, contract, and from the 20th century, conductor, conservative.
For more fun with words, see the Online Etymology Dictionary.
