Definition of confidence noun from the Oxford Advanced Learner's Dictionary

Oxford3000

confidence

noun
ˈkɒnfɪdəns
 
; ˈkɑːnfɪdəns
 
 
 

belief in others

1 [uncountable] confidence (in somebody/something) the feeling that you can trust, believe in and be sure about the abilities or good qualities of somebody/somethingThe players all have confidence in their manager.A fall in unemployment will help to restore consumer confidence.a lack of confidence in the governmentThe new contracts have undermined the confidence of employees.She has every confidence in her students' abilities. see also vote of confidence, vote of no confidence
 

belief in yourself

2 [uncountable] a belief in your own ability to do things and be successfulHe answered the questions with confidence.People often lose confidence when they are criticized.He gained confidence when he went to college.She suffers from a lack of confidence.While girls lack confidence, boys often overestimate their abilities.I didn't have any confidence in myself at school.
 

feeling certain

3 [uncountable] the feeling that you are certain about somethingThey could not say with confidence that he would be able to walk again after the accident.No one can predict with complete/total confidence what will happen in the financial markets.He expressed his confidence that they would win.
 

trust

4 [uncountable] a feeling of trust that somebody will keep information privateEva told me about their relationship in confidence.This is in the strictest confidence.It took a long time to gain her confidence (= make her feel she could trust me).
 

a secret

5 [countable] (formal) a secret that you tell somebodyThe girls exchanged confidences.I could never forgive Mike for betraying a confidence.
Idioms

be in somebody's confidence

to be trusted with somebody's secrets
He is said to be very much in the President's confidence.

take somebody into your confidence

to tell somebody secrets and personal information about yourself
She took me into her confidence and told me about the problems she was facing.