[字根 Root] aud, audi, audit, audio 聽見 to hear, listen

意思 Meaning：
1.信心、信任 faith, trust

1. confident 有信心的 feeling sure about your own ability to do things and be successful

2.confidential 機密的,秘密的 meant to be kept secret and not told to or shared with other people

3.fidelity 忠實、忠誠 the quality of being loyal to somebody/something

4.confidant 知己、密友 a person that you trust and who you talk to about private or secret things

5.diffidence 缺乏自信、羞怯 a lack of confidence in yourself; being unwilling to talk about yourself

6.infidel 異教徒 an offensive way of referring to somebody who does not believe in what the speaker considers to be the true religion